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<?xml version="1.0"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
  <!ENTITY tex "TeX">
  <!ENTITY latex "LaTeX">
]>
<book id="latex2e.dbk" lang="en">
  <title>&latex;2e reference manual (September 2009)</title>
<!-- %**end of header (This is for running Texinfo on a region.) -->
<!-- xx merge http://ctan.org/tex-archive/info/latex-info/ -->
<!-- xx check http://ctan.org/tex-archive/info/latexcheat -->
<!-- xx latex 2.09 should be complete, but latex2e stuff is missing. -->
<!-- xx The typeset source2e will have an index with all kernel -->
<!-- xx commands, which would be a good start.  classes.dtx et al. -->
<!-- xx define additional commands, and some of the kernel commands are -->
<!-- xx internal and so shouldn't be included here. -->
  <bookinfo>
    <legalnotice>
      <para>This document is an unofficial reference manual for &latex;, a
document preparation system, version as of September 2009.</para>
      <para>This was originally translated from <filename>LATEX.HLP</filename> v1.0a in the VMS
Help Library.  The pre-translation version was written by
George&#xa0;D. Greenwade of Sam Houston State University.  The
&latex;&#xa0;2.09 version was written by Stephen Gilmore.  The
&latex;2e version was adapted from this by Torsten Martinsen.  Karl
Berry made further updates and additions, and gratefully acknowledges
using <citetitle>Hypertext Help with &latex;</citetitle>, by Sheldon Green, and the
<citetitle>&latex; Command Summary</citetitle> (for &latex; 2.09) by L.&#xa0;Botway
and C.&#xa0;Biemesderfer (published by the &tex; Users Group as
<citetitle>&tex;niques</citetitle> number 10), as reference material (text was not
directly copied).</para>
      <para>Copyright &copy; 2007, 2008, 2009 Karl Berry.
Copyright &copy; 1988, 1994, 2007 Stephen Gilmore.
Copyright &copy; 1994, 1995, 1996 Torsten Martinsen.</para>
      <para>Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.</para>
      <para>Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.</para>
      <para>Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions.</para>
    </legalnotice>
</bookinfo>
  <chapter label="" xreflabel="LaTeX2e" id="Top">
    <title>&latex;2e</title>
    <para>This document is an unofficial reference manual for &latex;, a
document preparation system, version as of September 2009.  It is
intended to cover &latex;2e, which has been the standard version of
&latex; for many years.</para>
    <para><indexterm role="cp"><primary>Knuth, Donald E.</primary></indexterm><indexterm role="cp"><primary>Lamport, Leslie</primary></indexterm><indexterm role="cp"><primary>&latex; Project team</primary></indexterm>&latex; is implemented as a macro package for Donald&#xa0;E. Knuth's
&tex; typesetting program.  &latex; was originally created by Leslie
Lamport; it is now maintained by a group of volunteers
(<ulink url="http://latex-project.org">http://latex-project.org</ulink>).  The official documentation written
by the &latex; project is available there.  Again, the present
document is unofficial and has not been reviewed by the &latex;
maintainers.</para>
  </chapter>

  <chapter label="1" id="Overview">
    <title>Overview of &latex;</title>
    <para><indexterm role="cp"><primary>overview of &latex;</primary></indexterm><indexterm role="cp"><primary>&latex; overview</primary></indexterm>
The &latex; command typesets a file of text using the &tex; program
and the &latex; &ldquo;macro package&rdquo; for &tex;.  To be more specific,
it processes an input file containing the text of a document with
interspersed commands that describe how the text should be formatted.
It produces at least three files as output:</para>
    <orderedlist numeration="arabic">
      <listitem>
        <para>A main output file, which is one of:</para>
        <orderedlist numeration="arabic">
          <listitem>
            <para>If invoked as <command>latex</command>, a &ldquo;Device Independent&rdquo; (<filename>.dvi</filename>)
file. This contains commands that can be translated into commands for
a variety of output devices.  You can view such <filename>.dvi</filename> output of
&latex; by using a program such as <command>xdvi</command> (display directly)
or <command>dvips</command> (convert to PostScript).</para>
          </listitem>
          <listitem>
            <para>If invoked as <command>pdflatex</command>, a &ldquo;Portable Document Format&rdquo;
(<filename>.pdf</filename>) file.  Typically, this is a self-contained file, with
all fonts and images embedded.  This can be very useful, but it does
make the output much larger than the <filename>.dvi</filename> produced from the
same document.</para>
          </listitem>
        </orderedlist>
        <para>There are other less-common variants of &latex; (and &tex;) as well,
which can produce HTML, XML, and other things.</para>
      </listitem>
      <listitem>
        <para>A &ldquo;transcript&rdquo; or <filename>.log</filename> file that contains summary information and
diagnostic messages for any errors discovered in the input file.</para>
      </listitem>
      <listitem>
        <para>An &ldquo;auxiliary&rdquo; or <filename>.aux</filename> file. This is used by &latex; itself, for
things such as sectioning.</para>
      </listitem>
    </orderedlist>
    <para>A &latex; command begins with the command name, which consists of a
<literal>\</literal> followed by either (a)&#xa0;a string of letters or (b)&#xa0;a
single non-letter.  Arguments contained in square brackets, <literal>[]</literal>,
are optional while arguments contained in braces, <literal>{}</literal>, are
required.</para>
    <para>&latex; is case sensitive.  Enter all commands in lower case unless
explicitly directed to do otherwise.</para>
  </chapter>

  <chapter label="2" id="Starting-&-ending">
    <title>Starting &amp; ending</title>
    <para><indexterm role="cp"><primary>starting &amp; ending</primary></indexterm><indexterm role="cp"><primary>ending &amp; starting</primary></indexterm>
A minimal input file looks like the following:</para>
    <screen>
\documentclass{<replaceable>class</replaceable>}
\begin{document}
<replaceable>your text</replaceable>
\end{document}
</screen>
    <para role="continues">where the <replaceable>class</replaceable> is a valid document class for &latex;.
See <xref linkend="Document-classes"></xref>, for details of the various document classes
available locally.</para>
    <para><indexterm role="cp"><primary>preamble, defined</primary></indexterm>You may include other &latex; commands between the <literal>\documentclass</literal>
and the <literal>\begin{document}</literal> commands (this area is called the
<firstterm>preamble</firstterm>).</para>
  </chapter>

  <chapter label="3" id="Document-classes">
    <title>Document classes</title>
    <para><indexterm role="cp"><primary>document classes</primary></indexterm><indexterm role="cp"><primary>classes of documents</primary></indexterm><indexterm role="fn"><primary>\documentclass</primary></indexterm>
The class of a given document is defined with the command:</para>
    <screen>
\documentclass[<replaceable>options</replaceable>]{<replaceable>class</replaceable>}
</screen>
    <para role="continues">The <literal>\documentclass</literal> command must be the first command in a
&latex; source file.</para>
    <para><indexterm role="fn"><primary>article class</primary></indexterm><indexterm role="fn"><primary>report class</primary></indexterm><indexterm role="fn"><primary>book class</primary></indexterm><indexterm role="fn"><primary>letter class</primary></indexterm><indexterm role="fn"><primary>slides class</primary></indexterm>Built-in &latex; document <replaceable>class</replaceable> names are (many other document
classes are available as add-ons; see <xref linkend="Overview"></xref>):</para>
    <screen>
article  report  book  letter  slides
</screen>
<!-- xx briefly describe each one -->
    <para>Standard <replaceable>options</replaceable> are described below.</para>

    <sect1 label="3.1" id="Document-class-options">
      <title>Document class options</title>
      <para><indexterm role="cp"><primary>document class options</primary></indexterm><indexterm role="cp"><primary>options, document class</primary></indexterm><indexterm role="cp"><primary>class options</primary></indexterm><indexterm role="cp"><primary>global options</primary></indexterm>
You can specify so-called <firstterm>global options</firstterm> or <firstterm>class options</firstterm>
to the <literal>\documentclass</literal> command by enclosing them in square
brackets as usual.  To specify more than one <replaceable>option</replaceable>, separate
them with a comma:</para>
      <screen>
\documentclass[<replaceable>option1</replaceable>,<replaceable>option2</replaceable>,...]{<replaceable>class</replaceable>}
</screen>
      <para>Here is the list of the standard class options.</para>
      <para><indexterm role="fn"><primary>10pt option</primary></indexterm><indexterm role="fn"><primary>11pt option</primary></indexterm><indexterm role="fn"><primary>12pt option</primary></indexterm>All of the standard classes except <literal>slides</literal> accept the following
options for selecting the typeface size (default is <literal>10pt</literal>):</para>
      <screen>
10pt  11pt  12pt
</screen>
      <para><indexterm role="fn"><primary>a4paper option</primary></indexterm><indexterm role="fn"><primary>a5paper option</primary></indexterm><indexterm role="fn"><primary>b5paper option</primary></indexterm><indexterm role="fn"><primary>executivepaper option</primary></indexterm><indexterm role="fn"><primary>legalpaper option</primary></indexterm><indexterm role="fn"><primary>letterpaper option</primary></indexterm>All of the standard classes accept these options for selecting the paper
size (default is <literal>letterpaper</literal>):</para>
      <screen>
a4paper a5paper b5paper executivepaper legalpaper letterpaper
</screen>
      <para><indexterm role="fn"><primary>draft option</primary></indexterm><indexterm role="fn"><primary>final option</primary></indexterm><indexterm role="fn"><primary>fleqn option</primary></indexterm><indexterm role="fn"><primary>landscape option</primary></indexterm><indexterm role="fn"><primary>leqno option</primary></indexterm><indexterm role="fn"><primary>openbib option</primary></indexterm><indexterm role="fn"><primary>titlepage option</primary></indexterm><indexterm role="fn"><primary>notitlepage option</primary></indexterm>Miscellaneous other options:</para>
      <variablelist>
        <varlistentry>
          <term><literal>draft, final</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>black boxes, omitting</primary></indexterm>mark/do not mark overfull boxes with a big black box; default is <literal>final</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>fleqn</literal></term>
          <listitem>
            <para>Put displayed formulas flush left; default is centered.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>landscape</literal></term>
          <listitem>
            <para>Selects landscape format; default is portrait.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>leqno</literal></term>
          <listitem>
            <para>Put equation numbers on the left side of equations; default is the right side.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>openbib</literal></term>
          <listitem>
            <para>Use &ldquo;open&rdquo; bibliography format.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>titlepage, notitlepage</literal></term>
          <listitem>
            <para>Specifies whether the title page is separate; default depends on the class.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>These options are not available with the slides class:</para>
      <para><indexterm role="fn"><primary>onecolumn option</primary></indexterm><indexterm role="fn"><primary>twocolumn option</primary></indexterm><indexterm role="fn"><primary>oneside option</primary></indexterm><indexterm role="fn"><primary>twoside option</primary></indexterm><indexterm role="fn"><primary>openright option</primary></indexterm><indexterm role="fn"><primary>openany option</primary></indexterm></para>
      <variablelist>
        <varlistentry>
          <term><literal>onecolumn</literal></term>
          <term><literal>twocolumn</literal></term>
          <listitem>
            <para>Typeset in one or two columns; default is <literal>onecolumn</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>oneside</literal></term>
          <term><literal>twoside</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\evensidemargin</primary></indexterm><indexterm role="fn"><primary>\oddsidemargin</primary></indexterm>Selects one- or two-sided layout; default is <literal>oneside</literal>, except
for the <literal>book</literal> class.</para>
            <para>The <literal>\evensidemargin</literal> (<literal>\oddsidemargin</literal> parameter determines
the distance on even (odd) numbered pages between the left side of the
page and the text's left margin.  The defaults vary with the paper
size and whether one- or two-side layout is selected.  For one-sided
printing the text is centered, for two-sided, <literal>\oddsidemargin</literal> is
40% of the difference between <literal>\paperwidth</literal> and <literal>\textwidth</literal>
with <literal>\evensidemargin</literal> the remainder.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>openright</literal></term>
          <term><literal>openany</literal></term>
          <listitem>
            <para>Determines if a chapter should start on a
right-hand page; default is <literal>openright</literal> for book.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>The <literal>slides</literal> class offers the option <literal>clock</literal> for printing
the time at the bottom of each note.</para>
      <para><indexterm role="cp"><primary>packages, loading</primary></indexterm><indexterm role="cp"><primary>loading additional packages</primary></indexterm><indexterm role="fn"><primary>\usepackage</primary></indexterm>Additional packages are loaded like this:</para>
      <screen>
\usepackage[<replaceable>options</replaceable>]{<replaceable>pkg</replaceable>}
</screen>
      <para>To specify more than one <replaceable>pkg</replaceable>, you can separate them with a
comma, or use multiple <literal>\usepackage</literal> commands.</para>
      <para><indexterm role="cp"><primary>global options</primary></indexterm><indexterm role="cp"><primary>options, global</primary></indexterm>Any options given in the <literal>\documentclass</literal> command that are unknown
by the selected document class are passed on to the packages loaded with
<literal>\usepackage</literal>.</para>
    </sect1>
  </chapter>

  <chapter label="4" id="Typefaces">
    <title>Typefaces</title>
    <para><indexterm role="cp"><primary>typefaces</primary></indexterm><indexterm role="cp"><primary>fonts</primary></indexterm>
Two important aspects of selecting a <firstterm>font</firstterm> are specifying a size
and a style.  The &latex; commands for doing this are described here.</para>

    <sect1 label="4.1" id="Font-styles">
      <title>Font styles</title>
      <para><indexterm role="cp"><primary>font styles</primary></indexterm><indexterm role="cp"><primary>typeface styles</primary></indexterm><indexterm role="cp"><primary>styles of text</primary></indexterm>
The following type style commands are supported by &latex;.</para>
      <para>These commands are used like <literal>\textit{italic text}</literal>. The
corresponding command in parenthesis is the &ldquo;declaration form&rdquo;, which
takes no arguments. The scope of the declaration form lasts until the
next type style command or the end of the current group.</para>
      <para>The declaration forms are cumulative; i.e., you can say either
<literal>\sffamily\bfseries</literal> or <literal>\bfseries\sffamily</literal> to get bold
sans serif.</para>
      <para>You can also use the environment form of the declaration forms; for instance,
<literal>\begin{ttfamily}...\end{ttfamily}</literal>.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\textrm (\rmfamily)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textrm</primary></indexterm><indexterm role="fn"><primary>\rmfamily</primary></indexterm>Roman.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textit (\itshape)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textit</primary></indexterm><indexterm role="fn"><primary>\itshape</primary></indexterm>Italics.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\emph</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\emph</primary></indexterm><indexterm role="cp"><primary>emphasis</primary></indexterm>Emphasis (switches between <literal>\textit</literal> and <literal>\textrm</literal>).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textmd (\mdseries)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textmd</primary></indexterm><indexterm role="fn"><primary>\mdseries</primary></indexterm>Medium weight (default).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textbf (\bfseries)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textbf</primary></indexterm><indexterm role="fn"><primary>\bfseries</primary></indexterm>Boldface.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textup (\upshape)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textup</primary></indexterm><indexterm role="fn"><primary>\upshape</primary></indexterm>Upright (default). The opposite of slanted.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textsl (\slshape)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textsl</primary></indexterm><indexterm role="fn"><primary>\slshape</primary></indexterm>Slanted.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textsf (\sffamily)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textsf</primary></indexterm><indexterm role="fn"><primary>\sffamily</primary></indexterm>Sans serif.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textsc (\scshape)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textsc</primary></indexterm><indexterm role="fn"><primary>\scshape</primary></indexterm>Small caps.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\texttt (\ttfamily)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\texttt</primary></indexterm><indexterm role="fn"><primary>\ttfamily</primary></indexterm>Typewriter.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textnormal (\normalfont)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\textnormal</primary></indexterm><indexterm role="fn"><primary>\normalfont</primary></indexterm>Main document font.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathrm</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\mathrm</primary></indexterm>Roman, for use in math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathbf</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\mathbf</primary></indexterm>Boldface, for use in math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathsf</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\mathsf</primary></indexterm>Sans serif, for use in math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathtt</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\mathtt</primary></indexterm>Typewriter, for use in math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathit</literal></term>
          <term><literal>(\mit)</literal></term>
          <listitem>
            <para>Italics, for use in math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathnormal</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\mathnormal</primary></indexterm>For use in math mode, e.g. inside another type style declaration.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mathcal</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\mathcal</primary></indexterm>`Calligraphic' letters, for use in math mode.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>In addition, the command
<literal>\mathversion{bold}</literal>
<indexterm role="fn"><primary>\mathversion</primary></indexterm>can be used for switching to bold letters and symbols in
formulas. <literal>\mathversion{normal}</literal> restores the default.</para>
      <para>&latex; also provides these commands, which unconditionally switch to
the given style, that is, are <emphasis>not</emphasis> cumulative.  They are used
differently than the above commands, too: <literal>{\<replaceable>cmd</replaceable> ...}</literal>
instead of <literal>\<replaceable>cmd</replaceable>{...}</literal>.  These are two very different
things.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\bf</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>bold font</primary></indexterm>Switch to <emphasis role="bold">bold face</emphasis>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cal</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>script letters for math</primary></indexterm><indexterm role="cp"><primary>calligraphic letters for math</primary></indexterm>Switch to calligraphic letters for math.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\em</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>emphasis</primary></indexterm>Emphasis (italics within roman, roman within italics).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\it</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>italic font</primary></indexterm>Italics.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rm</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>roman font</primary></indexterm>Roman.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sc</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>small caps font</primary></indexterm>Small caps.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sf</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>sans serif font</primary></indexterm>Sans serif.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sl</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>slanted font</primary></indexterm><indexterm role="cp"><primary>oblique font</primary></indexterm>Slanted (oblique).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tt</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>typewriter font</primary></indexterm><indexterm role="cp"><primary>monospace font</primary></indexterm><indexterm role="cp"><primary>fixed-width font</primary></indexterm>Typewriter (monospace, fixed-width).</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="4.2" id="Font-sizes">
      <title>Font sizes</title>
      <para><indexterm role="cp"><primary>font sizes</primary></indexterm><indexterm role="cp"><primary>typeface sizes</primary></indexterm><indexterm role="cp"><primary>sizes of text</primary></indexterm>
The following standard type size commands are supported by &latex;.
The table shows the command name and the corresponding actual font
size used (in points) with the &lsquo;<literal>10pt</literal>&rsquo;, &lsquo;<literal>11pt</literal>&rsquo;, and
&lsquo;<literal>12pt</literal>&rsquo; document size options, respectively (see <xref linkend="Document-class-options"></xref>).</para>
      <para><indexterm role="fn"><primary>\tiny</primary></indexterm><indexterm role="fn"><primary>\scriptsize</primary></indexterm><indexterm role="fn"><primary>\footnotesize</primary></indexterm><indexterm role="fn"><primary>\small</primary></indexterm><indexterm role="fn"><primary>\normalsize</primary></indexterm><indexterm role="fn"><primary>\large</primary></indexterm><indexterm role="fn"><primary>\Large</primary></indexterm><indexterm role="fn"><primary>\LARGE</primary></indexterm><indexterm role="fn"><primary>\huge</primary></indexterm><indexterm role="fn"><primary>\Huge</primary></indexterm></para>
      <informaltable>
        <tgroup cols="4">
          <colspec colwidth="42*"></colspec>
          <colspec colwidth="7*"></colspec>
          <colspec colwidth="7*"></colspec>
          <colspec colwidth="7*"></colspec>
          <thead>
            <row>
              <entry>Command</entry>
              <entry><literal>10pt</literal></entry>
              <entry><literal>11pt</literal></entry>
              <entry><literal>12pt</literal></entry>
            </row>
          </thead>
          <tbody>
            <row>
              <entry><literal>\tiny</literal></entry>
              <entry>5</entry>
              <entry>6</entry>
              <entry>6</entry>
            </row>
            <row>
              <entry><literal>\scriptsize</literal></entry>
              <entry>7</entry>
              <entry>8</entry>
              <entry>8</entry>
            </row>
            <row>
              <entry><literal>\footnotesize</literal></entry>
              <entry>8</entry>
              <entry>9</entry>
              <entry>10</entry>
            </row>
            <row>
              <entry><literal>\small</literal></entry>
              <entry>9</entry>
              <entry>10</entry>
              <entry>10.95</entry>
            </row>
            <row>
              <entry><literal>\normalsize</literal> (default)</entry>
              <entry>10</entry>
              <entry>10.95</entry>
              <entry>12</entry>
            </row>
            <row>
              <entry><literal>\large</literal></entry>
              <entry>12</entry>
              <entry>12</entry>
              <entry>14.4</entry>
            </row>
            <row>
              <entry><literal>\Large</literal></entry>
              <entry>14.4</entry>
              <entry>14.4</entry>
              <entry>17.28</entry>
            </row>
            <row>
              <entry><literal>\LARGE</literal></entry>
              <entry>17.28</entry>
              <entry>17.28</entry>
              <entry>20.74</entry>
            </row>
            <row>
              <entry><literal>\huge</literal></entry>
              <entry>20.74</entry>
              <entry>20.74</entry>
              <entry>24.88</entry>
            </row>
            <row>
              <entry><literal>\Huge</literal></entry>
              <entry>24.88</entry>
              <entry>24.88</entry>
              <entry>24.88</entry>
            </row>
          </tbody>
        </tgroup>
      </informaltable>
      <para>The commands as listed here are &ldquo;declaration forms&rdquo;. The scope of
the declaration form lasts until the next type style command or the
end of the current group.  You can also use the environment form of
these commands; for instance, <literal>\begin{tiny}...\end{tiny}</literal>.</para>
    </sect1>

    <sect1 label="4.3" id="Low-level-font-commands">
      <title>Low-level font commands</title>
      <para><indexterm role="cp"><primary>low-level font commands</primary></indexterm><indexterm role="cp"><primary>font commands, low-level</primary></indexterm>
These commands are primarily intended for writers of macros and
packages.  The commands listed here are only a subset of the available
ones.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\fontencoding{enc}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\fontencoding</primary></indexterm>Select font encoding. Valid encodings include <literal>OT1</literal> and <literal>T1</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\fontfamily{family}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\fontfamily</primary></indexterm>Select font family. Valid families include:</para>
            <itemizedlist mark="bullet">
              <listitem>
                <para><literal>cmr</literal>  for Computer Modern Roman</para>
              </listitem>
              <listitem>
                <para><literal>cmss</literal> for Computer Modern Sans Serif</para>
              </listitem>
              <listitem>
                <para><literal>cmtt</literal> for Computer Modern Typewriter</para>
              </listitem>
            </itemizedlist>
            <para>and numerous others.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\fontseries{series}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\fontseries</primary></indexterm>Select font series. Valid series include:</para>
            <itemizedlist mark="bullet">
              <listitem>
                <para><literal>m</literal>  Medium (normal)</para>
              </listitem>
              <listitem>
                <para><literal>b</literal>  Bold</para>
              </listitem>
              <listitem>
                <para><literal>c</literal>  Condensed</para>
              </listitem>
              <listitem>
                <para><literal>bc</literal> Bold condensed</para>
              </listitem>
              <listitem>
                <para><literal>bx</literal> Bold extended</para>
              </listitem>
            </itemizedlist>
            <para>and various other combinations.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\fontshape{shape}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\fontshape</primary></indexterm>Select font shape. Valid shapes are:</para>
            <itemizedlist mark="bullet">
              <listitem>
                <para><literal>n</literal>  Upright (normal)</para>
              </listitem>
              <listitem>
                <para><literal>it</literal> Italic</para>
              </listitem>
              <listitem>
                <para><literal>sl</literal> Slanted (oblique)</para>
              </listitem>
              <listitem>
                <para><literal>sc</literal> Small caps</para>
              </listitem>
              <listitem>
                <para><literal>ui</literal> Upright italics</para>
              </listitem>
              <listitem>
                <para><literal>ol</literal> Outline</para>
              </listitem>
            </itemizedlist>
            <para>The two last shapes are not available for most font families.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\fontsize{size}{skip}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\fontsize</primary></indexterm><indexterm role="fn"><primary>\baselineskip</primary></indexterm>Set font size. The first parameter is the font size to switch to and
the second is the line spacing to use; this is stored in a parameter
named <literal>\baselineskip</literal>.  The unit of both parameters defaults to
pt.  The default <literal>\baselineskip</literal> for the Computer Modern typeface
is 1.2 times the <literal>\fontsize</literal>.</para>
            <para><indexterm role="fn"><primary>\baselinestretch</primary></indexterm><indexterm role="cp"><primary><literal>setspace</literal> package</primary></indexterm>The line spacing is also multiplied by the value of the
<literal>\baselinestretch</literal> parameter when the type size changes; the
default is 1.  However, the best way to &ldquo;double space&rdquo; a document,
if you should be unlucky enough to have to produce such, is to use the
<literal>setspace</literal> package; see
<ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=linespace">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=linespace</ulink>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\selectfont</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\selectfont</primary></indexterm>The changes made by calling the four font commands described above do
not come into effect until <literal>\selectfont</literal> is called.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\usefont{enc}{family}{series}{shape}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\usefont</primary></indexterm>The same as invoking <literal>\fontencoding</literal>, <literal>\fontfamily</literal>,
<literal>\fontseries</literal> and <literal>\fontshape</literal> with the given parameters,
followed by <literal>\selectfont</literal>.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>
  </chapter>

  <chapter label="5" id="Layout">
    <title>Layout</title>
    <para><indexterm role="cp"><primary>layout commands</primary></indexterm>
Miscellaneous commands for controlling the general layout of the page.</para>

    <sect1 label="5.1" id="\onecolumn">
      <title><literal>\onecolumn</literal></title>
      <para><indexterm role="fn"><primary>\onecolumn</primary></indexterm><indexterm role="cp"><primary>one-column output</primary></indexterm>
The <literal>\onecolumn</literal> declaration starts a new page and produces
single-column output.  This is the default.</para>
    </sect1>

    <sect1 label="5.2" id="\twocolumn">
      <title><literal>\twocolumn</literal></title>
      <para><indexterm role="fn"><primary>\twocolumn</primary></indexterm><indexterm role="cp"><primary>multicolumn text</primary></indexterm><indexterm role="cp"><primary>two-column output</primary></indexterm>
Synopsis:</para>
      <screen>
\twocolumn[<replaceable>text1col</replaceable>]
</screen>
      <para>The <literal>\twocolumn</literal> declaration starts a new page and produces
two-column output. If the optional <replaceable>text1col</replaceable> argument is present,
it is typeset in one-column mode before the two-column typesetting
starts.</para>
      <para>These parameters control typesetting in two-column output:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\columnsep</literal></term>
          <listitem>
            <para>The distance between columns (35pt by default).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\columnseprule</literal></term>
          <listitem>
            <para>The width of the rule between columns; the default is 0pt, so there is no rule.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\columnwidth</literal></term>
          <listitem>
            <para>The width of the current column; this is equal to <literal>\textwidth</literal> in
single-column text.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>These parameters control float behavior in two-column output:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\dbltopfraction</literal></term>
          <listitem>
            <para>Maximum fraction at the top of a two-column page that may be occupied
by floats.  Default &lsquo;<literal>.7</literal>&rsquo;, can be usefully redefined to (say)
&lsquo;<literal>.9</literal>&rsquo; to avoid going to float pages so soon.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dblfloatpagefraction</literal></term>
          <listitem>
            <para>The minimum fraction of a float page that must be occupied by floats,
for a two-column float page.  Default &lsquo;<literal>.5</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dblfloatsep</literal></term>
          <listitem>
            <para>Distance between floats at the top or bottom of a two-column float
page.  Default &lsquo;<literal>12pt plus2pt minus2pt</literal>&rsquo; for &lsquo;<literal>10pt</literal>&rsquo; and
&lsquo;<literal>11pt</literal>&rsquo; documents, &lsquo;<literal>14pt plus2pt minus4pt</literal>&rsquo; for &lsquo;<literal>12pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dbltextfloatsep</literal></term>
          <listitem>
            <para>Distance between a multi-column float at the top or bottom of a page
and the main text.  Default &lsquo;<literal>20pt plus2pt minus4pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="5.3" id="\flushbottom">
      <title><literal>\flushbottom</literal></title>
      <para><indexterm role="fn"><primary>\flushbottom</primary></indexterm>
The <literal>\flushbottom</literal> declaration makes all text pages the same
height, adding extra vertical space where necessary to fill out the
page.</para>
      <para>This is the default if <literal>twocolumn</literal> mode is selected
(see <xref linkend="Document-class-options"></xref>).</para>
    </sect1>

    <sect1 label="5.4" id="\raggedbottom">
      <title><literal>\raggedbottom</literal></title>
      <para><indexterm role="fn"><primary>\raggedbottom</primary></indexterm><indexterm role="cp"><primary>stretch, omitting vertical</primary></indexterm>
The <literal>\raggedbottom</literal> declaration makes all pages the natural
height of the material on that page.  No rubber lengths will be
stretched.</para>
    </sect1>

    <sect1 label="5.5" id="Page-layout-parameters">
      <title>Page layout parameters</title>
      <para><indexterm role="cp"><primary>page layout parameters</primary></indexterm><indexterm role="cp"><primary>parameters, page layout</primary></indexterm><indexterm role="cp"><primary>layout, page parameters for</primary></indexterm><indexterm role="cp"><primary>header, parameters for</primary></indexterm><indexterm role="cp"><primary>footer, parameters for</primary></indexterm><indexterm role="cp"><primary>running header and footer</primary></indexterm></para>
      <variablelist>
        <varlistentry>
          <term><literal>\headheight</literal></term>
          <listitem>
            <para>Height of the box that contains the running head.  Default is
&lsquo;<literal>30pt</literal>&rsquo;, except in the <literal>book</literal> class, where it varies with the
type size.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\headsep</literal></term>
          <listitem>
            <para>Vertical distance between the bottom of the header line and the top of
the main text.  Default is &lsquo;<literal>25pt</literal>&rsquo;, except in the <literal>book</literal>
class, where it varies with the type size.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\footskip</literal></term>
          <listitem>
            <para>Distance from the baseline of the last line of text to the baseline of
the page footer.  Default is &lsquo;<literal>30pt</literal>&rsquo;, except in the <literal>book</literal>
class, where it varies with the type size.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\linewidth</literal></term>
          <listitem>
            <para>Width of the current line; the default varies with the font size,
paper width, two-column mode, etc.  For an <literal>article</literal> document in
&lsquo;<literal>10pt</literal>&rsquo;, it's set to &lsquo;<literal>345pt</literal>&rsquo;; in two-column mode, that
becomes &lsquo;<literal>229.5pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textheight</literal></term>
          <listitem>
            <para>The normal vertical height of the page body; the default varies with
the font size, document class, etc.  For an <literal>article</literal> or
<literal>report</literal> document in &lsquo;<literal>10pt</literal>&rsquo;, it's set to
&lsquo;<literal>43\baselineskip</literal>&rsquo;; for <literal>book</literal>, it's &lsquo;<literal>41\baselineskip</literal>&rsquo;.
For &lsquo;<literal>11pt</literal>&rsquo;, it's &lsquo;<literal>38\baselineskip</literal>&rsquo; and for &lsquo;<literal>12pt</literal>&rsquo;,
&lsquo;<literal>36\baselineskip</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textwidth</literal></term>
          <listitem>
            <para>The normal horizontal width of the page body; the default varies as
usual.  For an <literal>article</literal> or <literal>report</literal> document, it's
&lsquo;<literal>345pt</literal>&rsquo; at &lsquo;<literal>10pt</literal>&rsquo;, &lsquo;<literal>360pt</literal>&rsquo; at &lsquo;<literal>11pt</literal>&rsquo;, and
&lsquo;<literal>390pt</literal>&rsquo; at &lsquo;<literal>12pt</literal>&rsquo;.  For a <literal>book</literal> document, it's
&lsquo;<literal>4.5in</literal>&rsquo; at &lsquo;<literal>10pt</literal>&rsquo;, and &lsquo;<literal>5in</literal>&rsquo; at &lsquo;<literal>11pt</literal>&rsquo; or &lsquo;<literal>12pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\topmargin</literal></term>
          <listitem>
            <para>Space between the top of the &tex; page (one inch from the top of the
paper, by default) and the top of the header.  The default is computed
based on many other parameters: <literal>\paperheight &minus; 2in &minus;
\headheight &minus; \headsep &minus; \textheight &minus; \footskip</literal>, and
then divided by two.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\topskip</literal></term>
          <listitem>
            <para>Minimum distance between the top of the page body and the baseline of
the first line of text.  For the standard clases, the default is the
same as the font size, e.g., &lsquo;<literal>10pt</literal>&rsquo; at &lsquo;<literal>10pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>
  </chapter>

  <chapter label="6" id="Sectioning">
    <title>Sectioning</title>
    <para><indexterm role="cp"><primary>sectioning</primary></indexterm>
Sectioning commands provide the means to structure your text into units:</para>
    <variablelist>
      <varlistentry>
        <term><literal>\part</literal></term>
        <term><literal>\chapter</literal></term>
        <listitem>
          <para>(report and book class only)</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term><literal>\section</literal></term>
        <term><literal>\subsection</literal></term>
        <term><literal>\subsubsection</literal></term>
        <term><literal>\paragraph</literal></term>
        <term><literal>\subparagraph</literal></term>
      </varlistentry>
    </variablelist>
    <para>All sectioning commands take the same general form, e.g.,</para>
    <screen>
\chapter[<replaceable>toctitle</replaceable>]{<replaceable>title</replaceable>}
</screen>
    <para>In addition to providing the heading <replaceable>title</replaceable> in the main text, the
section title can appear in two other places:</para>
    <orderedlist numeration="arabic">
      <listitem>
        <para>The table of contents.</para>
      </listitem>
      <listitem>
        <para>The running head at the top of the page.</para>
      </listitem>
    </orderedlist>
    <para>You may not want the same text in these places as in the main text.
To handle this, the sectioning commands have an optional argument
<replaceable>toctitle</replaceable> that, when given, specifies the text for these other
places.</para>
    <para><indexterm role="cp"><primary>*-form of sectioning commands</primary></indexterm>Also, all sectioning commands have <literal>*</literal>-forms that print
<replaceable>title</replaceable> as usual, but do not include a number and do not make an
entry in the table of contents.  For instance:</para>
    <screen>
\section*{Preamble}
</screen>
    <para><indexterm role="fn"><primary>\appendix</primary></indexterm><indexterm role="cp"><primary>appendix, creating</primary></indexterm>The <literal>\appendix</literal> command changes the way following sectional units
are numbered.  The <literal>\appendix</literal> command itself generates no text
and does not affect the numbering of parts.  The normal use of this
command is something like</para>
    <screen>
\chapter{A Chapter}
&hellip;
\appendix
\chapter{The First Appendix}
</screen>
  </chapter>

  <chapter label="7" id="Cross-references">
    <title>Cross references</title>
    <para><indexterm role="cp"><primary>cross references</primary></indexterm>
One reason for numbering things like figures and equations is to refer
the reader to them, as in &ldquo;See Figure 3 for more details.&rdquo;</para>

    <sect1 label="7.1" id="\label">
      <title><literal>\label</literal></title>
      <para><indexterm role="fn"><primary>\label</primary></indexterm>
Synopsis:</para>
      <screen>
\label{<replaceable>key</replaceable>}
</screen>
      <para>A <literal>\label</literal> command appearing in ordinary text assigns to
<replaceable>key</replaceable> the number of the current sectional unit; one appearing
inside a numbered environment assigns that number to <replaceable>key</replaceable>.</para>
      <para>A <replaceable>key</replaceable> name can consist of any sequence of letters, digits, or
punctuation characters.  Upper and lowercase letters are distinguished.</para>
      <para>To avoid accidentally creating two labels with the same name, it is
common to use labels consisting of a prefix and a suffix separated by
a colon or period. Some conventionally-used prefixes:</para>
      <variablelist>
        <varlistentry>
          <term><literal>ch</literal></term>
          <listitem>
            <para>for chapters</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>sec</literal></term>
          <listitem>
            <para>for lower-level sectioning commands</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>fig</literal></term>
          <listitem>
            <para>for figures</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>tab</literal></term>
          <listitem>
            <para>for tables</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>eq</literal></term>
          <listitem>
            <para>for equations</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>Thus, a label for a figure would look like <literal>fig:snark</literal> or
<literal>fig.snark</literal>.</para>
    </sect1>

    <sect1 label="7.2" id="\pageref">
      <title><literal>\pageref{<replaceable>key</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\pageref</primary></indexterm><indexterm role="cp"><primary>cross referencing with page number</primary></indexterm><indexterm role="cp"><primary>page number, cross referencing</primary></indexterm>
Synopsis:</para>
      <screen>
\pageref{<replaceable>key</replaceable>}
</screen>
      <para>The <literal>\pageref</literal>{<replaceable>key</replaceable>} command produces the page number of
the place in the text where the corresponding
<literal>\label</literal>{<replaceable>key</replaceable>} command appears.</para>
    </sect1>

    <sect1 label="7.3" id="\ref">
      <title><literal>\ref{<replaceable>key</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\ref</primary></indexterm><indexterm role="cp"><primary>cross referencing, symbolic</primary></indexterm><indexterm role="cp"><primary>section number, cross referencing</primary></indexterm><indexterm role="cp"><primary>equation number, cross referencing</primary></indexterm><indexterm role="cp"><primary>figure number, cross referencing</primary></indexterm><indexterm role="cp"><primary>footnote number, cross referencing</primary></indexterm>
Synopsis:</para>
      <screen>
\ref{<replaceable>key</replaceable>}
</screen>
      <para>The <literal>\ref</literal> command produces the number of the sectional unit,
equation, footnote, figure, &hellip;, of the corresponding
<literal>\label</literal> command (see <xref linkend="\label"></xref>).  It does not produce any text,
such as the word `Section' or `Figure', just the bare number itself.</para>
    </sect1>
  </chapter>

  <chapter label="8" id="Environments">
    <title>Environments</title>
    <para><indexterm role="cp"><primary>environments</primary></indexterm>
<indexterm role="fn"><primary>\begin</primary></indexterm><indexterm role="fn"><primary>\end</primary></indexterm>
&latex; provides many environments for marking off certain text.
Each environment begins and ends in the same manner:</para>
    <screen>
\begin{<replaceable>envname</replaceable>}
...
\end{<replaceable>envname</replaceable>}
</screen>
    <sect1 label="8.1" id="abstract">
      <title><literal>abstract</literal></title>
      <para><indexterm role="fn"><primary>abstract environment</primary></indexterm><indexterm role="cp"><primary>abstracts</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{abstract}
...
\end{abstract}
</screen>
      <para>Environment for producing an abstract, possibly of multiple paragraphs.</para>
    </sect1>

    <sect1 label="8.2" id="array">
      <title><literal>array</literal></title>
      <para><indexterm role="fn"><primary>array environment</primary></indexterm><indexterm role="cp"><primary>arrays, math</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{array}{<replaceable>template</replaceable>}
<replaceable>col1 text</replaceable>&amp;<replaceable>col1 text</replaceable>&amp;<replaceable>coln</replaceable>}\\
...
\end{array}
</screen>
      <para>Math arrays are produced with the <literal>array</literal> environment, normally
within an <literal>equation</literal> environment (see <xref linkend="equation"></xref>).  It has a
single mandatory <replaceable>template</replaceable> argument describing the number of
columns and the alignment within them.  Each column <replaceable>col</replaceable> is
specified by a single letter that tells how items in that row should
be formatted, as follows:</para>
      <variablelist>
        <varlistentry>
          <term><literal>c</literal></term>
          <listitem>
            <para>centered</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>l</literal></term>
          <listitem>
            <para>flush left</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>r</literal></term>
          <listitem>
            <para>flush right</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para><indexterm role="fn"><primary>\\ (for <literal>array</literal>)</primary></indexterm>Column entries are separated by <literal>&amp;</literal>.  Column entries may include
other &latex; commands.  Each row of the array is terminated with
<literal>\\</literal>.</para>
      <para><indexterm role="fn"><primary>@{...}</primary></indexterm>In the template, the construct <literal>@{<replaceable>text</replaceable>}</literal> puts <replaceable>text</replaceable>
between columns in each row.</para>
      <para>Here's an example:</para>
      <screen>
\begin{equation}
  \begin{array}{lrc}
  left1 &amp; right1 &amp; centered1 \\
  left2 &amp; right2 &amp; centered2 \\
  \end{array}
\end{equation}
</screen>
      <para><indexterm role="fn"><primary>\arraycolsep</primary></indexterm>The <literal>\arraycolsep</literal> parameter defines half the width of the space
separating columns; the default is &lsquo;<literal>5pt</literal>&rsquo;.  See <xref linkend="tabular"></xref>, for other
parameters which affect formatting in <literal>array</literal> environments,
namely <literal>\arrayrulewidth</literal> and <literal>\arraystretch</literal>.</para>
      <para>The <literal>array</literal> environment can only be used in math mode.</para>
    </sect1>

    <sect1 label="8.3" id="center">
      <title><literal>center</literal></title>
      <para><indexterm role="fn"><primary>center environment</primary></indexterm><indexterm role="cp"><primary>centering text, environment for</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{center}
<replaceable>line1</replaceable> \\
<replaceable>line2</replaceable> \\
\end{center}
</screen>
      <para><indexterm role="fn"><primary>\\ (for <literal>center</literal>)</primary></indexterm>The <literal>center</literal> environment allows you to create a paragraph
consisting of lines that are centered within the left and right
margins on the current page.  Each line is terminated with the
string <literal>\\</literal>.</para>

      <sect2 label="8.3.1" id="\centering">
        <title><literal>\centering</literal></title>
        <para><indexterm role="fn"><primary>\centering</primary></indexterm><indexterm role="cp"><primary>centering text, declaration for</primary></indexterm>
The <literal>\centering</literal> declaration corresponds to the <literal>center</literal>
environment.  This declaration can be used inside an environment such
as <literal>quote</literal> or in a <literal>parbox</literal>.  Thus, the text of a figure or
table can be centered on the page by putting a <literal>\centering</literal>
command at the beginning of the figure or table environment.</para>
        <para>Unlike the <literal>center</literal> environment, the <literal>\centering</literal> command
does not start a new paragraph; it simply changes how &latex; formats
paragraph units.  To affect a paragraph unit's format, the scope of
the declaration must contain the blank line or <literal>\end</literal> command (of
an environment such as quote) that ends the paragraph unit.</para>
        <para>Here's an example:</para>
        <screen>
\begin{quote}
\centering
first line \\
second line \\
\end{quote}
</screen>
      </sect2>
    </sect1>

    <sect1 label="8.4" id="description">
      <title><literal>description</literal></title>
      <para><indexterm role="fn"><primary>description environment</primary></indexterm><indexterm role="cp"><primary>labelled lists, creating</primary></indexterm><indexterm role="cp"><primary>description lists, creating</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{description}
\item [<replaceable>label1</replaceable>] <replaceable>item1</replaceable>
\item [<replaceable>label2</replaceable>] <replaceable>item2</replaceable>
...
\end{description}
</screen>
      <para><indexterm role="fn"><primary>\item</primary></indexterm>The <literal>description</literal> environment is used to make labelled lists.  Each
<replaceable>label</replaceable> is typeset in bold, flush right.  The <replaceable>item</replaceable> text may
contain multiple paragraphs.</para>
      <para><indexterm role="cp"><primary>bold typewriter, avoiding</primary></indexterm><indexterm role="cp"><primary>typewriter labels in lists</primary></indexterm>Another variation: since the bold style is applied to the labels, if
you typeset a label in typewriter using <literal>\texttt</literal>, you'll get
bold typewriter: <literal>\item[\texttt{bold and typewriter}]</literal>.  This
may be too bold, among other issues.  To get just typewriter, use
<literal>\tt</literal>, which resets all other style variations: <literal>\item[{\tt
plain typewriter}]</literal>.</para>
      <para>For details about list spacing, see <xref linkend="itemize"></xref>.</para>
    </sect1>

    <sect1 label="8.5" id="displaymath">
      <title><literal>displaymath</literal></title>
      <para><indexterm role="fn"><primary>displaymath environment</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{displaymath}
<replaceable>math</replaceable>
\end{displaymath}
</screen>
      <para role="continues">or</para>
      <screen>
\[<replaceable>math</replaceable>\]
</screen>
      <para>The <literal>displaymath</literal> environment (<literal>\[...\]</literal> is a synonym)
typesets the <replaceable>math</replaceable> text on its own line, centered by default.
The global <literal>fleqn</literal> option makes equations flush left; see
<xref linkend="Document-class-options"></xref>.</para>
      <para>No equation number is added to <literal>displaymath</literal> text; to get an
equation number, use the <literal>equation</literal> environment (see <xref linkend="equation"></xref>).</para>
    </sect1>

    <sect1 label="8.6" id="document">
      <title><literal>document</literal></title>
      <para><indexterm role="fn"><primary>document environment</primary></indexterm>
The <literal>document</literal> environment encloses the body of a document.
It is required in every &latex; document.  See <xref linkend="Starting-&-ending"></xref>.</para>
    </sect1>

    <sect1 label="8.7" id="enumerate">
      <title><literal>enumerate</literal></title>
      <para><indexterm role="fn"><primary>enumerate environment</primary></indexterm><indexterm role="cp"><primary>lists of items, numbered</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{enumerate}
\item <replaceable>item1</replaceable>
\item <replaceable>item2</replaceable>
...
\end{enumerate}
</screen>
      <para>The <literal>enumerate</literal> environment produces a numbered list.  Enumerations
can be nested within one another, up to four levels deep.  They can also
be nested within other paragraph-making environments, such as
<literal>itemize</literal> (see <xref linkend="itemize"></xref>) and <literal>description</literal>
(see <xref linkend="description"></xref>).</para>
      <para><indexterm role="fn"><primary>\item</primary></indexterm>Each item of an enumerated list begins with an <literal>\item</literal> command.
There must be at least one <literal>\item</literal> command within the environment.</para>
      <para>By default, the numbering at each level is done like this:</para>
      <orderedlist numeration="arabic">
        <listitem>
          <para>1., 2., &hellip;</para>
        </listitem>
        <listitem>
          <para>(a), (b), &hellip;</para>
        </listitem>
        <listitem>
          <para>i., ii., &hellip;</para>
        </listitem>
        <listitem>
          <para>A., B., &hellip;</para>
        </listitem>
      </orderedlist>
      <para><indexterm role="fn"><primary>\enumi</primary></indexterm><indexterm role="fn"><primary>\enumii</primary></indexterm><indexterm role="fn"><primary>\enumiii</primary></indexterm><indexterm role="fn"><primary>\enumiv</primary></indexterm>The <literal>enumerate</literal> environment uses the counters <literal>\enumi</literal>
through <literal>\enumiv</literal> counters (see <xref linkend="Counters"></xref>).  If the optional
argument to <literal>\item</literal> is given, the counter is not incremented for
that item.</para>
      <para><indexterm role="fn"><primary>\labelenumi</primary></indexterm><indexterm role="fn"><primary>\labelenumii</primary></indexterm><indexterm role="fn"><primary>\labelenumiii</primary></indexterm><indexterm role="fn"><primary>\labelenumiv</primary></indexterm>The <literal>enumerate</literal> environment uses the commands <literal>\labelenumi</literal>
through <literal>\labelenumiv</literal> to produce the default label.  So, you can
use <literal>\renewcommand</literal> to change the labels (see <xref linkend="\newcommand-&-\renewcommand"></xref>).  For instance, to have the first level use uppercase
letters:</para>
      <para><indexterm role="fn"><primary>\Alph example</primary></indexterm></para>
      <screen>
\renewcommand{\labelenumi}{\Alph{enumi}}
</screen>
    </sect1>

    <sect1 label="8.8" id="eqnarray">
      <title><literal>eqnarray</literal></title>
      <para><indexterm role="fn"><primary>eqnarray environment</primary></indexterm><indexterm role="cp"><primary>equations, aligning</primary></indexterm><indexterm role="cp"><primary>aligning Equations</primary></indexterm></para>
      <screen>
\begin{eqnarray}  <lineannotation>(or <literal>eqnarray*</literal>)</lineannotation>
<replaceable>formula1</replaceable> \\
<replaceable>formula2</replaceable> \\
...
\end{eqnarray}
</screen>
      <para><indexterm role="fn"><primary>\\ (for <literal>eqnarray</literal>)</primary></indexterm>The <literal>eqnarray</literal> environment is used to display a sequence of
equations or inequalities.  It is very much like a three-column
<literal>array</literal> environment, with consecutive rows separated by <literal>\\</literal>
and consecutive items within a row separated by an <literal>&amp;</literal>.</para>
      <para><indexterm role="fn"><primary>\\* (for <literal>eqnarray</literal>)</primary></indexterm><literal>\\*</literal> can also be used to separate equations, with its normal
meaning of not allowing a page break at that line.</para>
      <para><indexterm role="fn"><primary>\nonumber</primary></indexterm><indexterm role="cp"><primary>equation numbers, omitting</primary></indexterm>An equation number is placed on every line unless that line has a
<literal>\nonumber</literal> command.  Alternatively, The <literal>*</literal>-form of the
environment (<literal>\begin{eqnarray*} ... \end{eqnarray*}</literal>) will
omit equation numbering entirely, while otherwise being the same as
<literal>eqnarray</literal>.</para>
      <para><indexterm role="fn"><primary>\lefteqn</primary></indexterm>The command <literal>\lefteqn</literal> is used for splitting long formulas across
lines. It typesets its argument in display style flush left in a box of
zero width.</para>
    </sect1>

    <sect1 label="8.9" id="equation">
      <title><literal>equation</literal></title>
      <para><indexterm role="fn"><primary>equation environment</primary></indexterm><indexterm role="cp"><primary>equations, environment for</primary></indexterm><indexterm role="cp"><primary>formulas, environment for</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{equation}
<replaceable>math</replaceable>
\end{equation}
</screen>
      <para>The <literal>equation</literal> environment starts a <literal>displaymath</literal>
environment (see <xref linkend="displaymath"></xref>), e.g., centering the <replaceable>math</replaceable> text
on the page, and also places an equation number in the right margin.</para>
    </sect1>

    <sect1 label="8.10" id="figure">
      <title><literal>figure</literal></title>
      <para><indexterm role="fn"><primary>figure</primary></indexterm><indexterm role="cp"><primary>inserting figures</primary></indexterm><indexterm role="cp"><primary>figures, inserting</primary></indexterm></para>
      <screen>
\begin{figure[*]}[<replaceable>placement</replaceable>]
<replaceable>figbody</replaceable>
\label{<replaceable>label}</replaceable>
\caption[<replaceable>loftitle</replaceable>]{<replaceable>text</replaceable>}
\end{figure}
</screen>
      <para>Figures are objects that are not part of the normal text, and are
instead &ldquo;floated&rdquo; to a convenient place, such as the top of a page.
Figures will not be split between two pages.</para>
      <para>When typesetting in double-columns, the starred form produces a
full-width figure (across both columns).</para>
      <para>The optional argument <literal>[placement]</literal> determines where &latex; will try
to place your figure.  There are four places where &latex; can possibly
put a float:</para>
      <variablelist>
        <varlistentry>
          <term><literal>t</literal></term>
          <listitem>
            <para>(Top)&mdash;at the top of a text page.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>b</literal></term>
          <listitem>
            <para>(Bottom)&mdash;at the bottom of a text page.  However, <literal>b</literal> is not
allowed for full-width floats (<literal>figure*</literal>) with double-column
output.  To ameliorate this, use the <literal>stfloats</literal> or
<literal>dblfloatfix</literal> package, but see the discussion at caveats in the
FAQ: <ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=2colfloat">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=2colfloat</ulink>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>h</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary><literal>float</literal> package</primary></indexterm>(Here)&mdash;at the position in the text where the figure environment
appears.  However, this is not allowed by itself, <literal>t</literal> is
automatically added.  To absolutely force a figure to appear &ldquo;here&rdquo;,
use the <literal>float</literal> and use its <literal>H</literal> placement letter.  (That
package also provides other options.)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>p</literal></term>
          <listitem>
            <para>(Page of floats)&mdash;on a separate float page, which is a page
containing no text, only floats.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>The standard report and article classes use the default placement
<literal>tbp</literal>.</para>
      <para>The body of the figure is made up of whatever text, &latex; commands, etc.
you wish.</para>
      <para><indexterm role="fn"><primary>\caption</primary></indexterm>The <literal>\caption</literal> command specifies caption <replaceable>text</replaceable> for the
figure.  The caption is numbered by default.  If <replaceable>loftitle</replaceable> is
present, it is used in the list of figures instead of <replaceable>text</replaceable>
(see <xref linkend="Tables-of-contents"></xref>).</para>
<!-- xx float-placement, float-caption sections? -->
      <variablelist>
        <title><indexterm role="fn"><primary>\bottomfraction</primary></indexterm>The maximum fraction of the page allowed to be occuped by floats atthe bottom; default &lsquo;<literal>.3</literal>&rsquo;.</title>
        <varlistentry>
          <term><literal>\floatpagefraction</literal></term>
          <listitem>
            <para>The minimum fraction of a float page that must be occupied by floats;
default &lsquo;<literal>.5</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\floatsep</literal></term>
          <listitem>
            <para>Space between floats at the top or bottom of a page; default
&lsquo;<literal>12pt plus2pt minus2pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\intextsep</literal></term>
          <listitem>
            <para>Space above and below a float in the middle of the main text; default
&lsquo;<literal>12pt plus2pt minus2pt</literal>&rsquo; for &lsquo;<literal>10pt</literal>&rsquo; and &lsquo;<literal>11pt</literal>&rsquo; styles,
&lsquo;<literal>14pt plus4pt minus4pt</literal>&rsquo; for &lsquo;<literal>12pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textfloatsep</literal></term>
          <listitem>
            <para>Space between the last (first) float at the top (bottom) of a page;
default &lsquo;<literal>20pt plus2pt minus4pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\textfraction</literal></term>
          <listitem>
            <para>Minimum fraction of a page that must be text; if floats take up too
much space to preserve this much text, floats will be moved to a
different page.  The default is &lsquo;<literal>.2</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\topfraction</literal></term>
          <listitem>
            <para>Maximum fraction at the top of a page that may be occupied before
floats; default is &lsquo;<literal>.7</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="8.11" id="flushleft">
      <title><literal>flushleft</literal></title>
      <para><indexterm role="fn"><primary>flushleft environment</primary></indexterm><indexterm role="cp"><primary>left-justifying text, environment for</primary></indexterm><indexterm role="cp"><primary>ragged right text, environment for</primary></indexterm></para>
      <screen>
\begin{flushleft}
<replaceable>line1</replaceable> \\
<replaceable>line2</replaceable> \\
...
\end{flushleft}
</screen>
      <para><indexterm role="fn"><primary>\\ for <literal>flushleft</literal></primary></indexterm>The <literal>flushleft</literal> environment allows you to create a paragraph
consisting of lines that are flush to the left-hand margin and ragged
right Each line must be terminated with the string <literal>\\</literal>.</para>

      <sect2 label="8.11.1" id="\raggedright">
        <title><literal>\raggedright</literal></title>
        <para><indexterm role="fn"><primary>\raggedright</primary></indexterm><indexterm role="cp"><primary>ragged right text</primary></indexterm><indexterm role="cp"><primary>left-justifying text</primary></indexterm><indexterm role="cp"><primary>justification, ragged right</primary></indexterm>
The <literal>\raggedright</literal> declaration corresponds to the
<literal>flushleft</literal> environment.  This declaration can be used inside an
environment such as <literal>quote</literal> or in a <literal>parbox</literal>.</para>
        <para>Unlike the <literal>flushleft</literal> environment, the <literal>\raggedright</literal>
command does not start a new paragraph; it only changes how &latex;
formats paragraph units.  To affect a paragraph unit's format, the
scope of the declaration must contain the blank line or <literal>\end</literal>
command that ends the paragraph unit.</para>
      </sect2>
    </sect1>

    <sect1 label="8.12" id="flushright">
      <title><literal>flushright</literal></title>
      <para><indexterm role="fn"><primary>flushright environment</primary></indexterm><indexterm role="cp"><primary>ragged left text, environment for</primary></indexterm><indexterm role="cp"><primary>right-justifying text, environment for</primary></indexterm></para>
      <screen>
\begin{flushright}
<replaceable>line1</replaceable> \\
<replaceable>line2</replaceable> \\
...
\end{flushright}
</screen>
      <para><indexterm role="fn"><primary>\\ (for <literal>flushright</literal>)</primary></indexterm>The <literal>flushright</literal> environment allows you to create a paragraph
consisting of lines that are flush to the right-hand margin and ragged
left.  Each line must be terminated with the string <literal>\\</literal>.</para>

      <sect2 label="8.12.1" id="\raggedleft">
        <title><literal>\raggedleft</literal></title>
        <para><indexterm role="fn"><primary>\raggedleft</primary></indexterm><indexterm role="cp"><primary>ragged left text</primary></indexterm><indexterm role="cp"><primary>justification, ragged left</primary></indexterm><indexterm role="cp"><primary>right-justifying text</primary></indexterm>
The <literal>\raggedleft</literal> declaration corresponds to the
<literal>flushright</literal> environment.  This declaration can be used inside an
environment such as <literal>quote</literal> or in a <literal>parbox</literal>.</para>
        <para>Unlike the <literal>flushright</literal> environment, the <literal>\raggedleft</literal>
command does not start a new paragraph; it only changes how &latex;
formats paragraph units.  To affect a paragraph unit's format, the
scope of the declaration must contain the blank line or <literal>\end</literal>
command that ends the paragraph unit.</para>
      </sect2>
    </sect1>

    <sect1 label="8.13" id="itemize">
      <title><literal>itemize</literal></title>
      <para><indexterm role="fn"><primary>itemize environment</primary></indexterm><indexterm role="fn"><primary>\item</primary></indexterm><indexterm role="cp"><primary>lists of items</primary></indexterm><indexterm role="cp"><primary>unordered lists</primary></indexterm><indexterm role="cp"><primary>bulleted lists</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{itemize}
\item <replaceable>item1</replaceable>
\item <replaceable>item2</replaceable>
...
\end{itemize}
</screen>
      <para>The <literal>itemize</literal> environment produces an &ldquo;unordered&rdquo;, &ldquo;bulleted&rdquo;
list.  Itemizations can be nested within one another, up to four
levels deep.  They can also be nested within other paragraph-making
environments, such as <literal>enumerate</literal> (see <xref linkend="enumerate"></xref>).</para>
      <para>Each item of an <literal>itemize</literal> list begins with an <literal>\item</literal> command.
There must be at least one <literal>\item</literal> command within the environment.</para>
      <para>By default, the marks at each level look like this:</para>
      <orderedlist numeration="arabic">
        <listitem>
          <para>&bull; (bullet)</para>
        </listitem>
        <listitem>
          <para><emphasis role="bold">--<!-- /@w --></emphasis> (bold en-dash)</para>
        </listitem>
        <listitem>
          <para>* (asterisk)</para>
        </listitem>
        <listitem>
          <para>. (centered dot, rendered here as a period)</para>
        </listitem>
      </orderedlist>
      <para><indexterm role="fn"><primary>\labelitemi</primary></indexterm><indexterm role="fn"><primary>\labelitemii</primary></indexterm><indexterm role="fn"><primary>\labelitemiii</primary></indexterm><indexterm role="fn"><primary>\labelitemiv</primary></indexterm>The <literal>itemize</literal> environment uses the commands <literal>\labelitemi</literal>
through <literal>\labelitemiv</literal> to produce the default label.  So, you can
use <literal>\renewcommand</literal> to change the labels.  For instance, to have
the first level use diamonds:</para>
      <screen>
\renewcommand{\labelitemi}{$\diamond$}
</screen>
      <para><indexterm role="fn"><primary>\leftmargin</primary></indexterm><indexterm role="fn"><primary>\leftmargini</primary></indexterm><indexterm role="fn"><primary>\leftmarginii</primary></indexterm><indexterm role="fn"><primary>\leftmarginiii</primary></indexterm><indexterm role="fn"><primary>\leftmarginiv</primary></indexterm><indexterm role="fn"><primary>\leftmarginv</primary></indexterm><indexterm role="fn"><primary>\leftmarginvi</primary></indexterm>The <literal>\leftmargini</literal> through <literal>\leftmarginvi</literal> parameters define
the distance between the left margin of the enclosing environment and
the left margin of the list.  By convention, <literal>\leftmargin</literal> is set
to the appropriate <literal>\leftmargin<replaceable>N</replaceable></literal> when a new level of
nesting is entered.</para>
      <para>The defaults vary from &lsquo;<literal>.5em</literal>&rsquo; (highest levels of nesting) to
&lsquo;<literal>2.5em</literal>&rsquo; (first level), and are a bit reduced in two-column mode.
This example greatly reduces the margin space for outermost lists:</para>
      <screen>
\setlength{\leftmargini}{1.25em} % default 2.5em
</screen>
<!-- xx should be in its own generic section -->
      <para>Some parameters that affect list formatting:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\itemindent</literal></term>
          <listitem>
            <para>Extra indentation before each item in a list; default zero.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\labelsep</literal></term>
          <listitem>
            <para>Space between the label and text of an item; default &lsquo;<literal>.5em</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\labelwidth</literal></term>
          <listitem>
            <para>Width of the label; default &lsquo;<literal>2em</literal>&rsquo;, or &lsquo;<literal>1.5em</literal>&rsquo; in two-column mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\listparindent</literal></term>
          <listitem>
            <para>Extra indentation added to second and subsequent paragraphs within a
list item; default &lsquo;<literal>0pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rightmargin</literal></term>
          <listitem>
            <para>Horizontal distance between the right margin of the list and the
enclosing environment; default &lsquo;<literal>0pt</literal>&rsquo;, except in the <literal>quote</literal>,
<literal>quotation</literal>, and <literal>verse</literal> environments, where it is set equal
to <literal>\leftmargin</literal>.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>Parameters affecting vertical spacing between list items (rather
loose, by default).</para>
      <variablelist>
        <varlistentry>
          <term><literal>\itemsep</literal></term>
          <listitem>
            <para>Vertical space between items.  The default is <literal>2pt plus1pt
minus1pt</literal> for <literal>10pt</literal> documents, <literal>3pt plus2pt minus1pt</literal> for
<literal>11pt</literal>, and <literal>4.5pt plus2pt minus1pt</literal> for <literal>12pt</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\parsep</literal></term>
          <listitem>
            <para>Extra vertical space between paragraphs within a list item.  Defaults
are the same as <literal>\itemsep</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\topsep</literal></term>
          <listitem>
            <para>Vertical space between the first item and the preceding paragraph.
For top-level lists, the default is <literal>8pt plus2pt minus4pt</literal> for
<literal>10pt</literal> documents, <literal>9pt plus3pt minus5pt</literal> for <literal>11pt</literal>,
and <literal>10pt plus4pt minus6pt</literal> for <literal>12pt</literal>.  These are reduced
for nested lists.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\partopsep</literal></term>
          <listitem>
            <para>Extra space added to <literal>\topsep</literal> when the list environment starts a
paragraph.  The default is <literal>2pt plus1pt minus1pt</literal> for <literal>10pt</literal>
documents, <literal>3pt plus1pt minus1pt</literal> for <literal>11pt</literal>, and <literal>3pt
plus2pt minus2pt</literal> for <literal>12pt</literal>.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para><indexterm role="fn"><primary>\parskip example</primary></indexterm>Especially for lists with short items, it may be desirable to elide
space between items.  Here is an example defining an <literal>itemize*</literal>
environment with no extra spacing between items, or between paragraphs
within a single item (<literal>\parskip</literal> is not list-specific,
see <xref linkend="\parskip"></xref>):</para>
      <screen>
\newenvironment{itemize*}%
  {\begin{itemize}%
    \setlength{\itemsep}{0pt}%
    \setlength{\parsep}{0pt}}%
    \setlength{\parskip}{0pt}}%
  {\end{itemize}}
</screen>
    </sect1>

    <sect1 label="8.14" id="letter">
      <title><literal>letter</literal> environment: writing letters</title>
      <para><indexterm role="fn"><primary>letter</primary></indexterm>
This environment is used for creating letters.  See <xref linkend="Letters"></xref>.</para>
    </sect1>

    <sect1 label="8.15" id="list">
      <title><literal>list</literal></title>
      <para><indexterm role="fn"><primary>list</primary></indexterm><indexterm role="cp"><primary>lists of items, generic</primary></indexterm>
The <literal>list</literal> environment is a generic environment which is used for
defining many of the more specific environments. It is seldom used in
documents, but often in macros.</para>
      <screen>
\begin{list}{<replaceable>labeling</replaceable>}{<replaceable>spacing</replaceable>}
\item <replaceable>item1</replaceable>
\item <replaceable>item2</replaceable>
...
\end{list}
</screen>
      <para>The mandatory <replaceable>labeling</replaceable> argument specifies how items should be
labelled (unless the optional argument is supplied to <literal>\item</literal>).
This argument is a piece of text that is inserted in a box to form the
label.  It can and usually does contain other &latex; commands.</para>
      <para>The mandatory <replaceable>spacing</replaceable> argument contains commands to change the
spacing parameters for the list.  This argument will most often be
empty, i.e., <literal>{}</literal>, which leaves the default spacing.</para>
    </sect1>

    <sect1 label="8.16" id="math">
      <title><literal>math</literal></title>
      <para><indexterm role="fn"><primary>math environment</primary></indexterm><indexterm role="cp"><primary>in-line formulas</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{math}
<replaceable>math</replaceable>
\end{math}
</screen>
      <para>The <literal>math</literal> environment inserts the given <replaceable>math</replaceable> within the
running text.  <literal>\(...\))</literal> and <literal>$...$</literal> are synonyms.
See <xref linkend="Math-formulas"></xref>.</para>
    </sect1>

    <sect1 label="8.17" id="minipage">
      <title><literal>minipage</literal></title>
      <para><indexterm role="fn"><primary>minipage environment</primary></indexterm><indexterm role="cp"><primary>minipage, creating a</primary></indexterm></para>
      <screen>
\begin{minipage}[<replaceable>position</replaceable>][<replaceable>height</replaceable>][<replaceable>inner-pos</replaceable>]{<replaceable>width</replaceable>}
<replaceable>text</replaceable>
\end{minipage}
</screen>
      <para>The <literal>minipage</literal> environment typesets its body <replaceable>text</replaceable> in a
block that will not be broken across pages.  This is similar to the
<literal>\parbox</literal> command (see <xref linkend="\parbox"></xref>), but unlike <literal>\parbox</literal>,
other paragraph-making environments can be used inside a minipage.</para>
<!-- (xxref positions) -->
      <para>The arguments are the same as for <literal>\parbox</literal> (see <xref linkend="\parbox"></xref>).</para>
      <para><indexterm role="cp"><primary>indentation of paragraphs, in minipage</primary></indexterm><indexterm role="cp"><primary>paragraph indentation, in minipage</primary></indexterm><indexterm role="fn"><primary>\parindent</primary></indexterm>By default, paragraphs are not indented in the <literal>minipage</literal>
environment.  You can restore indentation with a command such as
<literal>\setlength{\parindent}{1pc}</literal> command.</para>
      <para><indexterm role="cp"><primary>footnotes in figures</primary></indexterm><indexterm role="cp"><primary>figures, footnotes in</primary></indexterm>Footnotes in a <literal>minipage</literal> environment are handled in a way that is
particularly useful for putting footnotes in figures or tables.  A
<literal>\footnote</literal> or <literal>\footnotetext</literal> command puts the footnote at
the bottom of the minipage instead of at the bottom of the page, and it
uses the <literal>\mpfootnote</literal> counter instead of the ordinary
<literal>footnote</literal> counter (see <xref linkend="Counters"></xref>).</para>
      <para>However, don't put one minipage inside another if you are using
footnotes; they may wind up at the bottom of the wrong minipage.</para>
    </sect1>

    <sect1 label="8.18" id="picture">
      <title><literal>picture</literal></title>
      <para><indexterm role="fn"><primary>picture</primary></indexterm><indexterm role="cp"><primary>creating pictures</primary></indexterm><indexterm role="cp"><primary>pictures, creating</primary></indexterm></para>
      <screen>
\begin{picture}(width,height)(x offset,y offset)
&hellip; <replaceable>picture commands</replaceable> &hellip;
\end{picture}
</screen>
      <para><indexterm role="fn"><primary>\unitlength</primary></indexterm>The <literal>picture</literal> environment allows you to create just about any
kind of picture you want containing text, lines, arrows and circles.
You tell &latex; where to put things in the picture by specifying
their coordinates.  A coordinate is a number that may have a decimal
point and a minus sign&mdash;a number like <literal>5</literal>, <literal>0.3</literal> or
<literal>-3.1416</literal>.  A coordinate specifies a length in multiples of the
unit length <literal>\unitlength</literal>, so if <literal>\unitlength</literal> has been set
to <literal>1cm</literal>, then the coordinate 2.54 specifies a length of 2.54
centimeters.  You should only change the value of <literal>\unitlength</literal>,
using the <literal>\setlength</literal> command, outside of a <literal>picture</literal>
environment.</para>
      <para>A position is a pair of coordinates, such as <literal>(2.4,-5)</literal>, specifying
the point with x-coordinate <literal>2.4</literal> and y-coordinate <literal>-5</literal>.
Coordinates are specified in the usual way with respect to an origin,
which is normally at the lower-left corner of the picture.  Note that
when a position appears as an argument, it is not enclosed in braces;
the parentheses serve to delimit the argument.</para>
      <para>The <literal>picture</literal> environment has one mandatory argument, which is a
<literal>position</literal>.  It specifies the size of the picture.  The environment
produces a rectangular box with width and height determined by this
argument's x- and y-coordinates.</para>
      <para>The <literal>picture</literal> environment also has an optional <literal>position</literal>
argument, following the <literal>size</literal> argument, that can change the
origin.  (Unlike ordinary optional arguments, this argument is not
contained in square brackets.) The optional argument gives the
coordinates of the point at the lower-left corner of the picture
(thereby determining the origin).  For example, if <literal>\unitlength</literal>
has been set to <literal>1mm</literal>, the command</para>
      <screen>
\begin{picture}(100,200)(10,20)
</screen>
      <para role="continues">produces a picture of width 100 millimeters and height 200
millimeters, whose lower-left corner is the point (10,20) and whose
upper-right corner is therefore the point (110,220).  When you first
draw a picture, you typically omit the optional argument, leaving the
origin at the lower-left corner.  If you then want to modify your
picture by shifting everything, you can just add the appropriate
optional argument.</para>
      <para>The environment's mandatory argument determines the nominal size of the
picture.  This need bear no relation to how large the picture really is;
&latex; will happily allow you to put things outside the picture, or even
off the page.  The picture's nominal size is used by &latex; in determining
how much room to leave for it.</para>
      <para>Everything that appears in a picture is drawn by the <literal>\put</literal>
command. The command</para>
      <screen>
\put (11.3,-.3){...}
</screen>
      <para role="continues">puts the object specified by <literal>...</literal> in the
picture, with its reference point at coordinates (11.3,-.3).
The reference points for various objects will be described below.</para>
      <para><indexterm role="fn"><primary>lR box</primary></indexterm>The <literal>\put</literal> command creates an <firstterm>LR box</firstterm>.  You can put anything
that can go in an <literal>\mbox</literal> (see <xref linkend="\mbox"></xref>) in the text argument of
the <literal>\put</literal> command.  When you do this, the reference point will
be the lower left corner of the box.</para>
      <para>The <literal>picture</literal> commands are described in the following sections.</para>

      <sect2 label="8.18.1" id="\circle">
        <title><literal>\circle</literal></title>
        <para><indexterm role="fn"><primary>\circle</primary></indexterm></para>
        <screen>
\circle[*]{<replaceable>diameter</replaceable>}
</screen>
        <para>The <literal>\circle</literal> command produces a circle with a diameter as close
to the specified one as possible.  The <literal>*</literal>-form of the command
draws a solid circle.</para>
        <para>Circles up to 40 pt can be drawn.</para>
      </sect2>

      <sect2 label="8.18.2" id="\makebox-(picture)">
        <title><literal>\makebox</literal></title>
        <para><indexterm role="fn"><primary>\makebox (picture)</primary></indexterm>
<literal>\makebox(width,height)[position]{...}</literal></para>
        <para>The <literal>\makebox</literal> command for the picture environment is similar to
the normal <literal>\makebox</literal> command except that you must specify a
<literal>width</literal> and <literal>height</literal> in multiples of <literal>\unitlength</literal>.</para>
        <para>The optional argument, <literal>[position]</literal>, specifies the quadrant that
your text appears in.  You may select up to two of the following:</para>
        <variablelist>
          <varlistentry>
            <term><literal>t</literal></term>
            <listitem>
              <para>Moves the item to the top of the rectangle.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>b</literal></term>
            <listitem>
              <para>Moves the item to the bottom.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>l</literal></term>
            <listitem>
              <para>Moves the item to the left.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>r</literal></term>
            <listitem>
              <para>Moves the item to the right.</para>
            </listitem>
          </varlistentry>
        </variablelist>
        <para>See <xref linkend="\makebox"></xref>.</para>
      </sect2>

      <sect2 label="8.18.3" id="\framebox-(picture)">
        <title><literal>\framebox</literal></title>
        <para><indexterm role="fn"><primary>\framebox</primary></indexterm>
Synopsis:</para>
        <screen>
\framebox(<replaceable>width</replaceable>,<replaceable>height</replaceable>)[<replaceable>pos</replaceable>]{...}
</screen>
        <para>The <literal>\framebox</literal> command is like <literal>\makebox</literal> (see previous
section), except that it puts a frame around the outside of the box
that it creates.</para>
        <para><indexterm role="fn"><primary>\fboxrule</primary></indexterm><indexterm role="fn"><primary>\fboxsep</primary></indexterm>The <literal>\framebox</literal> command produces a rule of thickness
<literal>\fboxrule</literal>, and leaves a space <literal>\fboxsep</literal> between the rule
and the contents of the box.</para>
      </sect2>

      <sect2 label="8.18.4" id="\dashbox">
        <title><literal>\dashbox</literal></title>
        <para><indexterm role="fn"><primary>\dashbox</primary></indexterm>
Draws a box with a dashed line.  Synopsis:</para>
        <screen>
\dashbox{<replaceable>dlen</replaceable>}(<replaceable>rwidth</replaceable>,<replaceable>rheight</replaceable>)[<replaceable>pos</replaceable>]{<replaceable>text</replaceable>}
</screen>
        <para><literal>\dashbox</literal> creates a dashed rectangle around <replaceable>text</replaceable> in a
<literal>picture</literal> environment.  Dashes are <replaceable>dlen</replaceable> units long, and the
rectangle has overall width <replaceable>rwidth</replaceable> and height <replaceable>rheight</replaceable>.
The <replaceable>text</replaceable> is positioned at optional <replaceable>pos</replaceable>.  
<!-- xxref positions. -->
A dashed box looks best when the <literal>rwidth</literal> and <literal>rheight</literal> are
multiples of the <literal>dlen</literal>.</para>
      </sect2>

      <sect2 label="8.18.5" id="\frame">
        <title><literal>\frame</literal></title>
        <para><indexterm role="fn"><primary>\frame</primary></indexterm>
Synopsis:</para>
        <screen>
\frame{<replaceable>text</replaceable>}
</screen>
        <para>The <literal>\frame</literal> command puts a rectangular frame around <replaceable>text</replaceable>.
The reference point is the bottom left corner of the frame.  No extra
space is put between the frame and the object.</para>
      </sect2>

      <sect2 label="8.18.6" id="\line">
        <title><literal>\line</literal></title>
        <para><indexterm role="fn"><primary>\line</primary></indexterm>
Synopsis:</para>
        <screen>
\line(<replaceable>xslope</replaceable>,<replaceable>yslope</replaceable>){<replaceable>length</replaceable>}
</screen>
        <para>The <literal>\line</literal> command draws a line with the given <replaceable>length</replaceable> and
slope <replaceable>xslope</replaceable>/<replaceable>yslope</replaceable>.</para>
        <para>Standard &latex; can only draw lines with <replaceable>slope</replaceable> = x/y,
where x and y have integer values from &minus;6
through&#xa0;6.  For lines of any slope, not to mention other shapes,
see the <literal>curve2e</literal> and many many other packages on CTAN.</para>
      </sect2>

      <sect2 label="8.18.7" id="\linethickness">
        <title><literal>\linethickness</literal></title>
        <para><indexterm role="fn"><primary>\linethickness</primary></indexterm>
The <literal>\linethickness{<replaceable>dim</replaceable>}</literal> command declares the thickness
of horizontal and vertical lines in a picture environment to be
<replaceable>dim</replaceable>, which must be a positive length.</para>
        <para><literal>\linethickness</literal> does not affect the thickness of slanted lines,
circles, or the quarter circles drawn by <literal>\oval</literal>.</para>
      </sect2>

      <sect2 label="8.18.8" id="\thicklines">
        <title><literal>\thicklines</literal></title>
        <para><indexterm role="fn"><primary>\thicklines</primary></indexterm>
The <literal>\thicklines</literal> command is an alternate line thickness for
horizontal and vertical lines in a picture environment;
cf.&#xa0;<xref linkend="\linethickness"></xref> and <xref linkend="\thinlines"></xref>.</para>
      </sect2>

      <sect2 label="8.18.9" id="\thinlines">
        <title><literal>\thinlines</literal></title>
        <para><indexterm role="fn"><primary>\thinlines</primary></indexterm>
The <literal>\thinlines</literal> command is the default line thickness for
horizontal and vertical lines in a picture environment;
cf.&#xa0;<xref linkend="\linethickness"></xref> and <xref linkend="\thicklines"></xref>.</para>
      </sect2>

      <sect2 label="8.18.10" id="\multiput">
        <title><literal>\multiput</literal></title>
        <para><indexterm role="fn"><primary>\multiput</primary></indexterm>
Synopsis:</para>
        <screen>
\multiput(<replaceable>x</replaceable>,<replaceable>y</replaceable>)(<replaceable>delta_x</replaceable>,<replaceable>delta_y</replaceable>){<replaceable>n</replaceable>}{<replaceable>obj</replaceable>}
</screen>
        <para>The <literal>\multiput</literal> command copies the object <replaceable>obj</replaceable> in a regular
pattern across a picture.  <replaceable>obj</replaceable> is first placed at position
(x,y), then at (x+\delta x,y+\delta y), and so on,
<replaceable>n</replaceable> times.</para>
      </sect2>

      <sect2 label="8.18.11" id="\oval">
        <title><literal>\oval</literal></title>
        <para><indexterm role="fn"><primary>\oval</primary></indexterm>
Synopsis:</para>
        <screen>
\oval(<replaceable>width</replaceable>,<replaceable>height</replaceable>)[<replaceable>portion</replaceable>]
</screen>
        <para>The <literal>\oval</literal> command produces a rectangle with rounded corners.
The optional argument <replaceable>portion</replaceable> allows you to select part of the
oval via the following:</para>
        <variablelist>
          <varlistentry>
            <term><literal>t</literal></term>
            <listitem>
              <para>selects the top portion;</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>b</literal></term>
            <listitem>
              <para>selects the bottom portion;</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>r</literal></term>
            <listitem>
              <para>selects the right portion;</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>l</literal></term>
            <listitem>
              <para>selects the left portion.</para>
            </listitem>
          </varlistentry>
        </variablelist>
        <para>The &ldquo;corners&rdquo; of the oval are made with quarter circles with a
maximum radius of 20pt, so large &ldquo;ovals&rdquo; will look more like
boxes with rounded corners.</para>
      </sect2>

      <sect2 label="8.18.12" id="\put">
        <title><literal>\put</literal></title>
        <para><indexterm role="fn"><primary>\put</primary></indexterm>
<literal>\put(x coord,y coord){ ...  }</literal></para>
        <para>The <literal>\put</literal> command places the item specified by the mandatory
argument at the given coordinates.</para>
      </sect2>

      <sect2 label="8.18.13" id="\shortstack">
        <title><literal>\shortstack</literal></title>
        <para><indexterm role="fn"><primary>\shortstack</primary></indexterm>
Synopsis:</para>
        <screen>
\shortstack[<replaceable>position</replaceable>]{...\\...\\...}
</screen>
        <para>The <literal>\shortstack</literal> command produces a stack of objects.  The valid
positions are:</para>
        <variablelist>
          <varlistentry>
            <term><literal>r</literal></term>
            <listitem>
              <para>Move the objects to the right of the stack.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>l</literal></term>
            <listitem>
              <para>Move the objects to the left of the stack</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>c</literal></term>
            <listitem>
              <para>Move the objects to the centre of the stack (default)</para>
            </listitem>
          </varlistentry>
        </variablelist>
        <para><indexterm role="fn"><primary>\\ (for <literal>\shortstack</literal> objects)</primary></indexterm>Objects are separated with <literal>\\</literal>.</para>
      </sect2>

      <sect2 label="8.18.14" id="\vector">
        <title><literal>\vector</literal></title>
        <para><indexterm role="fn"><primary>\vector</primary></indexterm>
Synopsis:</para>
        <screen>
\vector(<replaceable>x-slope</replaceable>,<replaceable>y-slope</replaceable>){<replaceable>length</replaceable>}
</screen>
        <para>The <literal>\vector</literal> command draws a line with an arrow of the specified
length and slope.  The x and y values must lie between
&minus;4 and +4, inclusive.</para>
      </sect2>
    </sect1>

    <sect1 label="8.19" id="quotation">
      <title><literal>quotation</literal></title>
      <para><indexterm role="fn"><primary>quotation</primary></indexterm><indexterm role="cp"><primary>quoted text with paragraph indentation, displaying</primary></indexterm><indexterm role="cp"><primary>displaying quoted text with paragraph indentation</primary></indexterm><indexterm role="cp"><primary>paragraph indentations in quoted text</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{quotation}
<replaceable>text</replaceable>
\end{quotation}
</screen>
      <para>The margins of the <literal>quotation</literal> environment are indented on both
the left and the right.  The text is justified at both margins.
Leaving a blank line between text produces a new paragraph.</para>
      <para>Unlike the <literal>quote</literal> environment, each paragraph is indented
normally.</para>
    </sect1>

    <sect1 label="8.20" id="quote">
      <title><literal>quote</literal></title>
      <para><indexterm role="fn"><primary>quote</primary></indexterm><indexterm role="cp"><primary>quoted text without paragraph indentation, displaying</primary></indexterm><indexterm role="cp"><primary>displaying quoted text without paragraph indentation</primary></indexterm><indexterm role="cp"><primary>paragraph indentations in quoted text, omitting</primary></indexterm>
Snyopsis:</para>
      <screen>
\begin{quote}
<replaceable>text</replaceable>
\end{quote}
</screen>
      <para>The margins of the <literal>quote</literal> environment are indented on both the
left and the right.  The text is justified at both margins.  Leaving a
blank line between text produces a new paragraph.</para>
      <para>Unlike the <literal>quotation</literal> environment, paragraphs are not indented.</para>
    </sect1>

    <sect1 label="8.21" id="tabbing">
      <title><literal>tabbing</literal></title>
      <para><indexterm role="fn"><primary>tabbing environment</primary></indexterm><indexterm role="cp"><primary>tab stops, using</primary></indexterm><indexterm role="cp"><primary>lining text up in columns using tab stops</primary></indexterm><indexterm role="cp"><primary>alignment via tabbing</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{tabbing}
<replaceable>row1col1</replaceable> \= <replaceable>row1col2</replaceable> \= <replaceable>row1col3</replaceable> \= <replaceable>row1col4</replaceable> \\
<replaceable>row2col1</replaceable> \&gt;                \&gt; <replaceable>row2col3</replaceable> \\
...
\end{tabbing}
</screen>
      <para>The <literal>tabbing</literal> environment provides a way to align text in
columns.  It works by setting tab stops and tabbing to them much as
was done on an ordinary typewriter.  It is best suited for cases where
the width of each column is constant and known in advance.</para>
      <para>This environment can be broken across pages, unlike the <literal>tabular</literal>
environment.</para>
      <para>The following commands can be used inside a <literal>tabbing</literal> enviroment:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\\ tabbing</literal></term>
          <listitem>
            <para>End a line.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\= (tabbing)</literal></term>
          <listitem>
            <para>Sets a tab stop at the current position.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\&gt; (tabbing)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\&gt;</primary></indexterm>Advances to the next tab stop.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\&lt;</literal></term>
          <listitem>
            <para>Put following text to the left of the local margin (without changing
the margin).  Can only be used at the start of the line.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\+</literal></term>
          <listitem>
            <para>Moves the left margin of the next and all the
following commands one tab stop to the right, beginning tabbed line if
necessary.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\-</literal></term>
          <listitem>
            <para>Moves the left margin of the next and all the
following commands one tab stop to the left, beginning tabbed line if
necessary.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\' (tabbing)</literal></term>
          <listitem>
            <para>Moves everything that you have typed so far in the
current column, i.e. everything from the most recent <literal>\&gt;</literal>,
<literal>\&lt;</literal>, <literal>\'</literal>, <literal>\\</literal>, or <literal>\kill</literal> command, to the right
of the previous column, flush against the current column's tab stop.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\` (tabbing)</literal></term>
          <listitem>
            <para>Allows you to put text flush right against any tab stop, including tab
stop&#xa0;0.  However, it can't move text to the right of the last column
because there's no tab stop there.  The <literal>\`</literal> command moves all the
text that follows it, up to the <literal>\\</literal> or <literal>\end{tabbing}</literal>
command that ends the line, to the right margin of the tabbing
environment.  There must be no <literal>\&gt;</literal> or <literal>\'</literal> command between
the <literal>\`</literal> and the command that ends the line.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\a (tabbing)</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\a' (acute accent in tabbing)</primary></indexterm><indexterm role="fn"><primary>\a` (grave accent in tabbing)</primary></indexterm><indexterm role="fn"><primary>\a= (macron accent in tabbing)</primary></indexterm>In a <literal>tabbing</literal> environment, the commands <literal>\=</literal>, <literal>\'</literal> and
<literal>\`</literal> do not produce accents as usual (see <xref linkend="Accents"></xref>).  Instead,
the commands <literal>\a=</literal>, <literal>\a'</literal> and <literal>\a`</literal> are used.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\kill</literal></term>
          <listitem>
            <para>Sets tab stops without producing text.  Works just like <literal>\\</literal>
except that it throws away the current line instead of producing
output for it.  The effect of any <literal>\=</literal>, <literal>\+</literal> or <literal>\-</literal>
commands in that line remain in effect.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\poptabs</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\poptabs</primary></indexterm>Restores the tab stop positions saved by the last <literal>\pushtabs</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\pushtabs</literal></term>
          <listitem>
            <para>Saves all current tab stop positions. Useful for temporarily changing
tab stop positions in the middle of a <literal>tabbing</literal> environment.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tabbingsep</literal></term>
          <listitem>
            <para>Distance to left of tab stop moved by <literal>\'</literal>.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>This example typesets a Pascal function in a traditional format:</para>
      <screen>
\begin{tabbing}
function \= fact(n : integer) : integer;\\
         \&gt; begin \= \+ \\
               \&gt; if \= n $&gt;$ 1 then \+ \\
                        fact := n * fact(n-1) \- \\
                  else \+ \\
                        fact := 1; \-\- \\
            end;\\
\end{tabbing}
</screen>
    </sect1>

    <sect1 label="8.22" id="table">
      <title><literal>table</literal></title>
      <para><indexterm role="fn"><primary>table</primary></indexterm><indexterm role="cp"><primary>tables, creating</primary></indexterm><indexterm role="cp"><primary>creating tables</primary></indexterm>
Synopsis:</para>
      <screen>
 \begin{table}[placement]

  body of the table

 \caption{table title}
 \end{table}
</screen>
      <para>Tables are objects that are not part of the normal text, and are
usually &ldquo;floated&rdquo; to a convenient place, like the top of a page.
Tables will not be split between two pages.</para>
      <para>The optional argument <literal>[placement]</literal> determines where &latex; will try
to place your table.  There are four places where &latex; can possibly put
a float; these are the same as that used with the <literal>figure</literal>
environment, and described there (see <xref linkend="figure"></xref>).</para>
      <para>The standard <literal>report</literal> and <literal>article</literal> classes use the default
placement <literal>[tbp]</literal>.</para>
      <para>The body of the table is made up of whatever text, &latex; commands, etc.,
you wish.  The <literal>\caption</literal> command allows you to title your table.</para>
    </sect1>

    <sect1 label="8.23" id="tabular">
      <title><literal>tabular</literal></title>
      <para><indexterm role="fn"><primary>tabular environment</primary></indexterm><indexterm role="cp"><primary>lines in tables</primary></indexterm><indexterm role="cp"><primary>lining text up in tables</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{tabular}[pos]{cols}
column 1 entry &amp; column 2 entry ... &amp; column n entry \\
...
\end{tabular}
</screen>        
      <para>or</para>
      <screen>
\begin{tabular*}{width}[pos]{cols}
column 1 entry &amp; column 2 entry ... &amp; column n entry \\
...
\end{tabular*}
</screen>
      <para>These environments produce a box consisting of a sequence of rows of
items, aligned vertically in columns.</para>
      <para><indexterm role="fn"><primary>\\ for <literal>tabular</literal></primary></indexterm><literal>\\</literal> must be used to specify the end of each row of the table,
except for the last, where it is optional&mdash;unless an <literal>\hline</literal>
command (to put a rule below the table) follows.</para>
      <para>The mandatory and optional arguments consist of:</para>
      <variablelist>
        <varlistentry>
          <term><literal>width</literal></term>
          <listitem>
            <para>Specifies the width of the <literal>tabular*</literal> environment.  There must be
rubber space between columns that can stretch to fill out the specified
width.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>pos</literal></term>
          <listitem>
            <para>Specifies the vertical position; default is alignment on the centre of
the environment.</para>
            <variablelist>
              <varlistentry>
                <term><literal>t</literal></term>
                <listitem>
                  <para>align on top row</para>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal>b</literal></term>
                <listitem>
                  <para>align on bottom row</para>
                </listitem>
              </varlistentry>
            </variablelist>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>cols</literal></term>
          <listitem>
            <para>Specifies the column formatting.  It consists of a sequence of the
following specifiers, corresponding to the sequence of columns and
intercolumn material.</para>
            <variablelist>
              <varlistentry>
                <term><literal>l</literal></term>
                <listitem>
                  <para>A column of left-aligned items.</para>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal>r</literal></term>
                <listitem>
                  <para>A column of right-aligned items.</para>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal></literal></term>
                <listitem>
                  <para>A column of centred items.</para>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal>|</literal></term>
                <listitem>
                  <para>A vertical line the full height and depth of the environment.</para>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal>@{<replaceable>text</replaceable>}</literal></term>
                <listitem>
                  <para>This inserts <replaceable>text</replaceable> in every row.  An @-expression suppresses the
intercolumn space normally inserted between columns; any desired space
between the inserted text and the adjacent items must be included in
text.  An <literal>\extracolsep{wd}</literal> command in an @-expression causes
an extra space of width <literal>wd</literal> to appear to the left of all
subsequent columns, until countermanded by another <literal>\extracolsep</literal>
command.  Unlike ordinary intercolumn space, this extra space is not
suppressed by an @-expression.  An <literal>\extracolsep</literal> command can be
used only in an @-expression in the <literal>cols</literal> argument.</para>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal>p{<replaceable>wd</replaceable>}</literal></term>
                <listitem>
                  <para>Produces a column with each item typeset in a parbox of width
<replaceable>wd</replaceable>, as if it were the argument of a
<literal>\parbox[t]{<replaceable>wd</replaceable>}</literal> command.  However, a <literal>\\</literal> may not
appear in the item, except in the following situations:</para>
                  <orderedlist numeration="arabic">
                    <listitem>
                      <para>inside an environment like <literal>minipage</literal>, <literal>array</literal>, or <literal>tabular</literal>.</para>
                    </listitem>
                    <listitem>
                      <para>inside an explicit <literal>\parbox</literal>.</para>
                    </listitem>
                    <listitem>
                      <para>in the scope of a <literal>\centering</literal>, <literal>\raggedright</literal>, or <literal>\raggedleft</literal>
declaration.  The latter declarations must appear inside braces or an
environment when used in a <literal>p</literal>-column element.</para>
                    </listitem>
                  </orderedlist>
                </listitem>
              </varlistentry>
              <varlistentry>
                <term><literal>*{<replaceable>num</replaceable>}{<replaceable>cols</replaceable>}</literal></term>
                <listitem>
                  <para>Equivalent to <replaceable>num</replaceable> copies of <replaceable>cols</replaceable>, where <replaceable>num</replaceable> is a
positive integer and <replaceable>cols</replaceable> is any list of column-specifiers,
which may contain another <literal>*-expression</literal>.</para>
                </listitem>
              </varlistentry>
            </variablelist>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>Parameters that control formatting:
<!-- xx defaults, own node (xref from array)? --></para>
      <variablelist>
        <varlistentry>
          <term><literal>\arrayrulewidth</literal></term>
          <listitem>
            <para>Thickness of the rule created by <literal>|</literal>, <literal>\hline</literal>, and
<literal>\vline</literal> in the <literal>tabular</literal> and <literal>array</literal> environments; the
default is &lsquo;<literal>.4pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\arraystretch</literal></term>
          <listitem>
            <para>Scaling of spacing between rows in the <literal>tabular</literal> and <literal>array</literal>
environments; default is &lsquo;<literal>1</literal>&rsquo;, for no scaling.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\doublerulesep</literal></term>
          <listitem>
            <para>Horizontal distance between the vertical rules produced by <literal>||</literal>
in the <literal>tabular</literal> and <literal>array</literal> environments; default is &lsquo;<literal>2pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tabcolsep</literal></term>
          <listitem>
            <para>Half the width of the space between columns; default is &lsquo;<literal>6pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>These commands can be used inside a <literal>tabular</literal> environment:</para>

      <sect2 label="8.23.1" id="\multicolumn">
        <title><literal>\multicolumn</literal></title>
        <para><indexterm role="fn"><primary>\multicolumn</primary></indexterm>
Synopsis:</para>
        <screen>
\multicolumn{<replaceable>cols</replaceable>}{<replaceable>pos</replaceable>}{<replaceable>text</replaceable>}
</screen>
        <para>The <literal>\multicolumn</literal> command makes an entry that spans several
columns.  The first mandatory argument, <replaceable>cols</replaceable>, specifies the
number of columns to span.  The second mandatory argument, <replaceable>pos</replaceable>,
specifies the formatting of the entry; <literal>c</literal> for centered, <literal>l</literal>
for flushleft, <literal>r</literal> for flushright.  The third mandatory argument,
<replaceable>text</replaceable>, specifies what text to put in the entry.</para>
        <para>Here's an example showing two columns separated by an en-dash;
<literal>\multicolumn</literal> is used for the heading:</para>
        <screen>
\begin{tabular}{r@{--}l}
\multicolumn{2}{c}{\bf Unicode}\cr
   0x80&amp;0x7FF   \cr
  0x800&amp;0xFFFF  \cr
0x10000&amp;0x1FFFF \cr
\end{tabular}
</screen>
      </sect2>

      <sect2 label="8.23.2" id="\cline">
        <title><literal>\cline</literal></title>
        <para><indexterm role="fn"><primary>\cline</primary></indexterm>
Synopsis:</para>
        <screen>
\cline{<replaceable>i</replaceable>-<replaceable>j</replaceable>}
</screen>
        <para>The <literal>\cline</literal> command draws horizontal lines across the columns
specified, beginning in column <replaceable>i</replaceable> and ending in column <replaceable>j</replaceable>,
which are specified in the mandatory argument.</para>
      </sect2>

      <sect2 label="8.23.3" id="\hline">
        <title><literal>\hline</literal></title>
        <para><indexterm role="fn"><primary>\hline</primary></indexterm>
The <literal>\hline</literal> command draws a horizontal line the width of the
enclosing <literal>tabular</literal> or <literal>array</literal> environment.  It's most
commonly used to draw a line at the top, bottom, and between the rows
of a table.</para>
      </sect2>

      <sect2 label="8.23.4" id="\vline">
        <title><literal>\vline</literal></title>
        <para><indexterm role="fn"><primary>\vline</primary></indexterm>
The <literal>\vline</literal> command will draw a vertical line extending the full
height and depth of its row.  An <literal>\hfill</literal> command can be used to
move the line to the edge of the column.  It can also be used in an
@-expression.</para>
      </sect2>
    </sect1>

    <sect1 label="8.24" id="thebibliography">
      <title><literal>thebibliography</literal></title>
      <para><indexterm role="fn"><primary>thebibliography</primary></indexterm><indexterm role="cp"><primary>bibliography, creating (manually)</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{thebibliography}{<replaceable>widest-label</replaceable>}
\bibitem[<replaceable>label</replaceable>]{<replaceable>cite_key}</replaceable>
...
\end{thebibliography}
</screen>
      <para>The <literal>thebibliography</literal> environment produces a bibliography or
reference list.</para>
      <para>In the <literal>article</literal> class, this reference list is labelled
&ldquo;References&rdquo;; in the <literal>report</literal> class, it is labelled
&ldquo;Bibliography&rdquo;.  You can change the label (in the standard classes)
by redefining the command <literal>\refname</literal>.  For instance, this
eliminates it entirely:</para>
      <screen>
\renewcommand{\refname}{}
</screen>
      <para>The mandatory <replaceable>widest-label</replaceable> argument is text that, when typeset,
is as wide as the widest item label produced by the <literal>\bibitem</literal>
commands.  It is typically given as <literal>9</literal> for bibliographies with
less than 10 references, <literal>99</literal> for ones with less than 100, etc.</para>

      <sect2 label="8.24.1" id="\bibitem">
        <title><literal>\bibitem</literal></title>
        <para><indexterm role="fn"><primary>\bibitem</primary></indexterm>
Synopsis:</para>
        <screen>
\bibitem[<replaceable>label</replaceable>]{<replaceable>cite_key</replaceable>}
</screen>
        <para>The <literal>\bibitem</literal> command generates an entry labelled by
<replaceable>label</replaceable>.  If the <replaceable>label</replaceable> argument is missing, a number is
automatically generated using the <literal>enumi</literal> counter.  The
<replaceable>cite_key</replaceable> is any sequence of letters, numbers, and punctuation
symbols not containing a comma.</para>
        <para>This command writes an entry to the <filename>.aux</filename> file containing the
item's <replaceable>cite_key</replaceable> and label.  When the <filename>.aux</filename> file is read by
the <literal>\begin{document}</literal> command, the item's <literal>label</literal> is
associated with <literal>cite_key</literal>, causing references to <replaceable>cite_key</replaceable>
with a <literal>\cite</literal> command (see next section) to produce the
associated label.</para>
      </sect2>

      <sect2 label="8.24.2" id="\cite">
        <title><literal>\cite</literal></title>
        <para><indexterm role="fn"><primary>\cite</primary></indexterm>
Synopsis:</para>
        <screen>
\cite[<replaceable>subcite</replaceable>]{<replaceable>keys</replaceable>
</screen>
        <para>The <replaceable>keys</replaceable> argument is a list of one or more citation keys,
separated by commas.  This command generates an in-text citation to
the references associated with <replaceable>keys</replaceable> by entries in the
<filename>.aux</filename> file.</para>
        <para>The text of the optional <replaceable>subcite</replaceable> argument appears after the
citation.  For example, <literal>\cite[p.~314]{knuth}</literal> might produce
`[Knuth, p.&#xa0;314]'.</para>
      </sect2>

      <sect2 label="8.24.3" id="\nocite">
        <title><literal>\nocite</literal></title>
        <para><indexterm role="fn"><primary>\nocite</primary></indexterm>
<literal>\nocite{key_list}</literal></para>
        <para>The <literal>\nocite</literal> command produces no text, but writes <literal>key_list</literal>,
which is a list of one or more citation keys, on the <filename>.aux</filename> file.</para>
      </sect2>

      <sect2 label="8.24.4" id="Using-BibTeX">
        <title>Using Bib&tex;</title>
        <para><indexterm role="cp"><primary>using Bib&tex;</primary></indexterm><indexterm role="cp"><primary>bib&tex;, using</primary></indexterm><indexterm role="cp"><primary>bibliography, creating (automatically)</primary></indexterm><indexterm role="fn"><primary>\bibliographystyle</primary></indexterm><indexterm role="fn"><primary>\bibliography</primary></indexterm>
If you use the Bib&tex; program by Oren Patashnik (highly
recommended if you need a bibliography of more than a couple of
titles) to maintain your bibliography, you don't use the
<literal>thebibliography</literal> environment (see <xref linkend="thebibliography"></xref>). Instead,
you include the lines</para>
        <screen>
\bibliographystyle{<replaceable>bibstyle</replaceable>}
\bibliography{<replaceable>bibfile1</replaceable>,<replaceable>bibfile2</replaceable>}
</screen>
        <para>The <literal>\bibliographystyle</literal> command does not produce any output of
its own.  Rather, it defines the style in which the bibliography will
be produced: <replaceable>bibstyle</replaceable> refers to a file
<replaceable>bibstyle</replaceable><filename>.bst</filename>, which defines how your citations will look.
The standard <replaceable>style</replaceable> names distributed with Bib&tex; are:</para>
        <variablelist>
          <varlistentry>
            <term><literal>alpha</literal></term>
            <listitem>
              <para>Sorted alphabetically. Labels are formed from name of author and year of
publication.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>plain</literal></term>
            <listitem>
              <para>Sorted alphabetically. Labels are numeric.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>unsrt</literal></term>
            <listitem>
              <para>Like <literal>plain</literal>, but entries are in order of citation.</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><literal>abbrv</literal></term>
            <listitem>
              <para>Like <literal>plain</literal>, but more compact labels.</para>
            </listitem>
          </varlistentry>
        </variablelist>
        <para>In addition, numerous other Bib&tex; style files exist tailored to
the demands of various publications.  See
<ulink url="http://www.ctan.org/tex-archive/biblio/bibtex/contrib">http://www.ctan.org/tex-archive/biblio/bibtex/contrib</ulink>.</para>
        <para>The <literal>\bibliography</literal> command is what actually produces the
bibliography.  The argument to <literal>\bibliography</literal> refers to files
named <filename><replaceable>bibfile</replaceable>.bib</filename>, which should contain your database in
Bib&tex; format.  Only the entries referred to via <literal>\cite</literal> and
<literal>\nocite</literal> will be listed in the bibliography.</para>
      </sect2>
    </sect1>

    <sect1 label="8.25" id="theorem">
      <title><literal>theorem</literal></title>
      <para><indexterm role="fn"><primary>theorem environment</primary></indexterm><indexterm role="cp"><primary>theorems, typesetting</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{theorem}
<replaceable>theorem-text</replaceable>
\end{theorem}
</screen>
      <para>The <literal>theorem</literal> environment produces &ldquo;Theorem <replaceable>n</replaceable>&rdquo; in
boldface followed by <replaceable>theorem-text</replaceable>, where the numbering
possibilities for <replaceable>n</replaceable> are described under <literal>\newtheorem</literal>
(see <xref linkend="\newtheorem"></xref>).</para>
    </sect1>

    <sect1 label="8.26" id="titlepage">
      <title><literal>titlepage</literal></title>
      <para><indexterm role="fn"><primary>titlepage environment</primary></indexterm><indexterm role="cp"><primary>making a title page</primary></indexterm><indexterm role="cp"><primary>title pages, creating</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{titlepage}
<replaceable>text</replaceable>
\end{titlepage}
</screen>
      <para>The <literal>titlepage</literal> environment creates a title page, i.e., a page
with no printed page number or heading.  It also causes the following
page to be numbered page one.  Formatting the title page is left to
you.  The <literal>\today</literal> command may be useful on title pages
(see <xref linkend="\today"></xref>).</para>
      <para>You can use the <literal>\maketitle</literal> command (see <xref linkend="\maketitle"></xref>) to
produce a standard title page without a <literal>titlepage</literal> environment.</para>
    </sect1>

    <sect1 label="8.27" id="verbatim">
      <title><literal>verbatim</literal></title>
      <para><indexterm role="fn"><primary>verbatim environment</primary></indexterm><indexterm role="cp"><primary>verbatim text</primary></indexterm><indexterm role="cp"><primary>simulating typed text</primary></indexterm><indexterm role="cp"><primary>typed text, simulating</primary></indexterm><indexterm role="cp"><primary>code, typesetting</primary></indexterm><indexterm role="cp"><primary>computer programs, typesetting</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{verbatim}
<replaceable>literal-text</replaceable>
\end{verbatim}
</screen>
      <para>The <literal>verbatim</literal> environment is a paragraph-making environment in
which &latex; produces exactly what you type in; for instance the
<literal>\</literal> character produces a printed &lsquo;<literal>\</literal>&rsquo;.  It turns &latex;
into a typewriter with carriage returns and blanks having the same
effect that they would on a typewriter.</para>
      <para>The <literal>verbatim</literal> uses a monospaced typewriter-like font (<literal>\tt</literal>).</para>

      <sect2 label="8.27.1" id="\verb">
        <title><literal>\verb</literal></title>
        <para><indexterm role="fn"><primary>\verb</primary></indexterm><indexterm role="cp"><primary>verbatim text, inline</primary></indexterm>
Synopsis:</para>
        <screen>
\verb<replaceable>char</replaceable><replaceable>literal-text</replaceable><replaceable>char</replaceable>
\verb*<replaceable>char</replaceable><replaceable>literal-text</replaceable><replaceable>char</replaceable>
</screen>
        <para>The <literal>\verb</literal> command typesets <replaceable>literal-text</replaceable> as it is input,
including special characters and spaces, using the typewriter
(<literal>\tt</literal>) font.  No spaces are allowed between <literal>\verb</literal> or
<literal>\verb*</literal> and the delimiter <replaceable>char</replaceable>, which begins and ends the
verbatim text.  The delimiter must not appear in <replaceable>literal-text</replaceable>.</para>
        <para><indexterm role="cp"><primary>visible space</primary></indexterm>The <literal>*</literal>-form differs only in that spaces are printed with a
&ldquo;visible space&rdquo; character.</para>
      </sect2>
    </sect1>

    <sect1 label="8.28" id="verse">
      <title><literal>verse</literal></title>
      <para><indexterm role="fn"><primary>verse environment</primary></indexterm><indexterm role="cp"><primary>poetry, an environment for</primary></indexterm>
Synopsis:</para>
      <screen>
\begin{verse}
<replaceable>line1</replaceable> \\
<replaceable>line2</replaceable> \\
...
\end{verse}
</screen>
      <para>The <literal>verse</literal> environment is designed for poetry, though you may find
other uses for it.</para>
      <para><indexterm role="fn"><primary>\\ for <literal>verse</literal></primary></indexterm>The margins are indented on the left and the right, paragraphs are not
indented, and the text is not justified.  Separate the lines of each
stanza with <literal>\\</literal>, and use one or more blank lines to separate the
stanzas.</para>
    </sect1>
  </chapter>

  <chapter label="9" id="Footnotes">
    <title>Footnotes</title>
    <para><indexterm role="cp"><primary>footnotes, creating</primary></indexterm>
Footnotes can be produced in one of two ways.  They can be produced
with one command, the <literal>\footnote</literal> command.  They can also be
produced with two commands, the <literal>\footnotemark</literal> and the
<literal>\footnotetext</literal> commands.</para>

    <sect1 label="9.1" id="\footnote">
      <title><literal>\footnote</literal></title>
      <para><indexterm role="fn"><primary>\footnote</primary></indexterm>
Synopsis:</para>
      <screen>
\footnote[<replaceable>number</replaceable>]{<replaceable>text</replaceable>}
</screen>
      <para>The <literal>\footnote</literal> command places the numbered footnote <replaceable>text</replaceable>
at the bottom of the current page.  The optional argument <replaceable>number</replaceable>
changes the default footnote number.</para>
      <para>This command can only be used in outer paragraph mode; i.e., you
cannot use it in sectioning commands like <literal>\chapter</literal>, in figures,
tables or in a <literal>tabular</literal> environment.  (See following sections.)
<!-- xx mention packages that fix this --></para>
    </sect1>

    <sect1 label="9.2" id="\footnotemark">
      <title><literal>\footnotemark</literal></title>
      <para><indexterm role="fn"><primary>\footnotemark</primary></indexterm>
With no optional argument, the <literal>\footnotemark</literal> command puts the
current footnote number in the text.  This command can be used in
inner paragraph mode.  You give the text of the footnote separately,
with the <literal>\footnotetext</literal> command.</para>
      <para>This command can be used to produce several consecutive footnote
markers referring to the same footnote with</para>
      <screen>
\footnotemark[\value{footnote}]
</screen>
      <para>after the first <literal>\footnote</literal> command.</para>
    </sect1>

    <sect1 label="9.3" id="\footnotetext">
      <title><literal>\footnotetext</literal></title>
      <para><indexterm role="fn"><primary>\footnotetext</primary></indexterm>
Synopsis:</para>
      <screen>
\footnotetext[<replaceable>number</replaceable>]{<replaceable>text</replaceable>}
</screen>
      <para>The <literal>\footnotetext</literal> command places <replaceable>text</replaceable> at the bottom of
the page as a footnote.  This command can come anywhere after the
<literal>\footnotemark</literal> command.  The <literal>\footnotetext</literal> command must
appear in outer paragraph mode.</para>
      <para>The optional argument <replaceable>number</replaceable> changes the default footnote number.</para>
    </sect1>

    <sect1 label="9.4" id="Footnote-parameters">
      <title>Footnote parameters</title>
      <para><indexterm role="cp"><primary>footnote parameters</primary></indexterm></para>
      <variablelist>
        <varlistentry>
          <term><literal>\footnoterule</literal></term>
          <listitem>
            <para>Produces the rule separating the main text on a page from the page's
footnotes.  Default dimensions: <literal>0.4pt</literal> thick (or wide), and
<literal>0.4\columnwidth</literal> long in the standard document classes (except
slides, where it does not appear).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\footnotesep</literal></term>
          <listitem>
            <para>The height of the strut placed at the beginning of the footnote.  By
default, this is set to the normal strut for <literal>\footnotesize</literal>
fonts (see <xref linkend="Font-sizes"></xref>), therefore there is no extra space between
footnotes.  This is &lsquo;<literal>6.65pt</literal>&rsquo; for &lsquo;<literal>10pt</literal>&rsquo;, &lsquo;<literal>7.7pt</literal>&rsquo; for
&lsquo;<literal>11pt</literal>&rsquo;, and &lsquo;<literal>8.4pt</literal>&rsquo; for &lsquo;<literal>12pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>
  </chapter>

  <chapter label="10" id="Definitions">
    <title>Definitions</title>
    <para><indexterm role="cp"><primary>definitions</primary></indexterm>
&latex; has support for making new commands of many different kinds.</para>
<!-- xx everything in this chapter needs examples. -->
    <sect1 label="10.1" id="\newcommand-&-\renewcommand">
      <title><literal>\newcommand</literal> &amp; <literal>\renewcommand</literal></title>
      <para><indexterm role="fn"><primary>\newcommand</primary></indexterm><indexterm role="cp"><primary>commands, defining new ones</primary></indexterm><indexterm role="cp"><primary>defining a new command</primary></indexterm><indexterm role="cp"><primary>new commands, defining</primary></indexterm>
<literal>\newcommand</literal> and <literal>\renewcommand</literal> define and redefine a
command, respectively.  Synopses:</para>
      <screen>
  \newcommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
\renewcommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
  \newcommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>default</replaceable>]{<replaceable>defn</replaceable>}
\renewcommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>default</replaceable>]{<replaceable>defn</replaceable>}
</screen>
      <variablelist>
        <varlistentry>
          <term><replaceable>cmd</replaceable></term>
          <listitem>
            <para>The command name beginning with <literal>\</literal>.  For <literal>\newcommand</literal>, it
must not be already defined and must not begin with <literal>\end</literal>; for
<literal>\renewcommand</literal>, it must already be defined.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>nargs</replaceable></term>
          <listitem>
            <para>An optional integer from 1 to 9 specifying the number of arguments
that the command will take.  The default is for the command to have no
arguments.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>default</replaceable></term>
          <listitem>
            <para>If this optional parameter is present, it means that the command's
first argument is optional.  When the new command is called, the
default value of the optional argument (i.e., if it is not specified
in the call) is the string &lsquo;<literal>def</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>defn</replaceable></term>
          <listitem>
            <para>The text to be substituted for every occurrence of <literal>cmd</literal>; a
construct of the form <literal>#<replaceable>n</replaceable></literal> in <replaceable>defn</replaceable> is replaced by the
text of the <replaceable>n</replaceable>th argument.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="10.2" id="\newcounter">
      <title><literal>\newcounter</literal></title>
      <para><indexterm role="fn"><primary>\newcounter</primary></indexterm><indexterm role="cp"><primary>counters, defining new</primary></indexterm>
Synopsis:</para>
      <screen>
\newcounter{<replaceable>cnt</replaceable>}[<replaceable>countername</replaceable>]
</screen>
      <para>The <literal>\newcounter</literal> command defines a new counter named <replaceable>cnt</replaceable>.
The new counter is initialized to zero.</para>
      <para>Given the optional argument <literal>[<replaceable>countername</replaceable>]</literal>, <replaceable>cnt</replaceable>
will be reset whenever <replaceable>countername</replaceable> is incremented.</para>
      <para>See <xref linkend="Counters"></xref>, for more information about counters.</para>
    </sect1>

    <sect1 label="10.3" id="\newlength">
      <title><literal>\newlength</literal></title>
      <para><indexterm role="fn"><primary>\newlength</primary></indexterm><indexterm role="cp"><primary>lengths, defining new</primary></indexterm>
Synopsis:</para>
      <screen>
\newlength{\<replaceable>arg</replaceable>}
</screen>
      <para>The <literal>\newlength</literal> command defines the mandatory argument as a
<literal>length</literal> command with a value of <literal>0in</literal>.  The argument must
be a control sequence, as in <literal>\newlength{\foo}</literal>.  An error
occurs if <literal>\foo</literal> is already defined.</para>
      <para>See <xref linkend="Lengths"></xref>, for how to set the new length to a nonzero value, and
for more information about lengths in general.</para>
    </sect1>

    <sect1 label="10.4" id="\newsavebox">
      <title><literal>\newsavebox</literal></title>
      <para><indexterm role="fn"><primary>\newsavebox</primary></indexterm>
Synopsis:</para>
      <screen>
\newsavebox{<replaceable>cmd</replaceable>}
</screen>
      <para>Defines <literal>\<replaceable>cmd</replaceable></literal>, which must be a command name not already
defined, to refer to a new bin for storing boxes.</para>
    </sect1>

    <sect1 label="10.5" id="\newenvironment-&-\renewenvironment">
      <title><literal>\newenvironment</literal> &amp; <literal>\renewenvironment</literal></title>
      <para><indexterm role="fn"><primary>\newenvironment</primary></indexterm><indexterm role="fn"><primary>\renewenvironment</primary></indexterm><indexterm role="cp"><primary>environments, defining</primary></indexterm><indexterm role="cp"><primary>defining new environments</primary></indexterm><indexterm role="cp"><primary>redefining environments</primary></indexterm>
Synopses:</para>
      <screen>
  \newenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
  \newenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>default</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
\renewenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
</screen>
      <para>These commands define or redefine an environment <replaceable>env</replaceable>, that is,
<literal>\begin{<replaceable>env</replaceable>} &hellip; \end{<replaceable>env</replaceable>}</literal>.</para>
      <variablelist>
        <varlistentry>
          <term><replaceable>env</replaceable></term>
          <listitem>
            <para>The name of the environment.  For <literal>\newenvironment</literal>, <replaceable>env</replaceable>
must not be an existing environment, and the command <literal>\<replaceable>env</replaceable></literal>
must be undefined.  For <literal>\renewenvironment</literal>, <replaceable>env</replaceable> must be
the name of an existing environment.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>nargs</replaceable></term>
          <listitem>
            <para>An integer from 1 to 9 denoting the number of arguments of
the newly-defined environment.  The default is no arguments.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>default</replaceable></term>
          <listitem>
            <para>If this is specified, the first argument is optional, and <replaceable>default</replaceable>
gives the default value for that argument.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>begdef</replaceable></term>
          <listitem>
            <para>The text expanded at every occurrence of <literal>\begin{<replaceable>env</replaceable>}</literal>; a
construct of the form <literal>#<replaceable>n</replaceable></literal> in <replaceable>begdef</replaceable> is replaced by
the text of the <replaceable>n</replaceable>th argument.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>enddef</replaceable></term>
          <listitem>
            <para>The text expanded at every occurrence of <literal>\end{<replaceable>env</replaceable>}</literal>.  It
may not contain any argument parameters.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="10.6" id="\newtheorem">
      <title><literal>\newtheorem</literal></title>
      <para><indexterm role="fn"><primary>\newtheorem</primary></indexterm><indexterm role="cp"><primary>theorems, defining</primary></indexterm><indexterm role="cp"><primary>defining new theorems</primary></indexterm></para>
      <screen>
\newtheorem{<replaceable>newenv</replaceable>}{<replaceable>label</replaceable>}[<replaceable>within</replaceable>]
\newtheorem{<replaceable>newenv</replaceable>}[<replaceable>numbered_like</replaceable>]{<replaceable>label</replaceable>}
</screen>
      <para>This command defines a theorem-like environment.  Arguments:</para>
      <variablelist>
        <varlistentry>
          <term><replaceable>newenv</replaceable></term>
          <listitem>
            <para>The name of the environment to be defined; must not be the name of an
existing environment or otherwise defined.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>label</replaceable></term>
          <listitem>
            <para>The text printed at the beginning of the environment, before the
number. For example, &lsquo;<literal>Theorem</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>numbered_like</replaceable></term>
          <listitem>
            <para>(Optional.)  The name of an already defined theorem-like environment;
the new environment will be numbered just like <replaceable>numbered_like</replaceable>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>within</replaceable></term>
          <listitem>
            <para>(Optional.)  The name of an already defined counter, a sectional unit.
The new theorem counter will be reset at the same time as the
<replaceable>within</replaceable> counter.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>At most one of <replaceable>numbered_like</replaceable> and <replaceable>within</replaceable> can be specified,
not both.</para>
    </sect1>

    <sect1 label="10.7" id="\newfont">
      <title><literal>\newfont</literal></title>
      <para><indexterm role="fn"><primary>\newfont</primary></indexterm><indexterm role="cp"><primary>fonts, new commands for</primary></indexterm><indexterm role="cp"><primary>defining new fonts</primary></indexterm>
Synopsis:</para>
      <screen>
\newfont{<replaceable>cmd</replaceable>}{<replaceable>fontname</replaceable>}
</screen>
      <para>Defines a control sequence <literal>\<replaceable>cmd</replaceable></literal>, which must not already
be defined, to make <replaceable>fontname</replaceable> be the current font.  The file
looked for on the system is named <filename><replaceable>fontname</replaceable>.tfm</filename>.</para>
      <para>This is a low-level command for setting up to use an individual font.
More commonly, fonts are defined in families through <filename>.fd</filename> files.</para>
    </sect1>

    <sect1 label="10.8" id="\protect">
      <title><literal>\protect</literal></title>
      <para><indexterm role="fn"><primary>\protect</primary></indexterm>
<indexterm role="cp"><primary>fragile commands</primary></indexterm><indexterm role="cp"><primary>moving arguments</primary></indexterm>Footnotes, line breaks, any command that has an optional argument, and
many more are so-called <firstterm>fragile</firstterm> commands.  When a fragile
command is used in certain contexts, called <firstterm>moving arguments</firstterm>, it
must be preceded by <literal>\protect</literal>.  In addition, any fragile
commands within the arguments must have their own <literal>\protect</literal>.</para>
      <para>Some examples of moving arguments are <literal>\caption</literal>
(see <xref linkend="figure"></xref>), <literal>\thanks</literal> (see <xref linkend="\maketitle"></xref>), and
expressions in <literal>tabular</literal> and <literal>array</literal> environments
(see <xref linkend="tabular"></xref>).</para>
      <para><indexterm role="cp"><primary>robust commands</primary></indexterm>Commands which are not fragile are called <firstterm>robust</firstterm>.  They must not
be preceded by <literal>\protect</literal>.</para>
      <para>See also:</para>
      <screen>
<lineannotation><ulink url="http://www-h.eng.cam.ac.uk/help/tpl/textprocessing/teTeX/latex/latex2e-html/fragile.html">http://www-h.eng.cam.ac.uk/help/tpl/textprocessing/teTeX/latex/latex2e-html/fragile.html</ulink></lineannotation>
<lineannotation><ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=protect">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=protect</ulink></lineannotation>
</screen>
<!-- xx really need examples. -->
    </sect1>
  </chapter>

  <chapter label="11" id="Counters">
    <title>Counters</title>
    <para><indexterm role="cp"><primary>counters, a list of</primary></indexterm><indexterm role="cp"><primary>variables, a list of</primary></indexterm>
Everything &latex; numbers for you has a counter associated with
it. The name of the counter is the same as the name of the environment
or command that produces the number, except with no <literal>\</literal>.
(<literal>enumi</literal>&ndash;<literal>enumiv</literal> are used for the nested enumerate
environment.)  Below is a list of the counters used in &latex;'s
standard document classes to control numbering.</para>
    <screen>
part            paragraph       figure          enumi
chapter         subparagraph    table           enumii
section         page            footnote        enumiii
subsection      equation        mpfootnote      enumiv
subsubsection
</screen>
    <sect1 label="11.1" id="\alph-\Alph-\arabic-\roman-\Roman-\fnsymbol">
      <title><literal>\alph \Alph \arabic \roman \Roman \fnsymbol</literal>: Printing counters</title>
      <para>All of these commands take a single counter as an argument, for
instance, <literal>\alph{enumi}</literal>.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\alph</literal></term>
          <listitem>
            <para>prints <replaceable>counter</replaceable> using lowercase letters: `a', `b', &hellip;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Alph</literal></term>
          <listitem>
            <para>uses uppercase letters: `A', `B', &hellip;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\arabic</literal></term>
          <listitem>
            <para>uses Arabic numbers: `1', `2', &hellip;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\roman</literal></term>
          <listitem>
            <para>uses lowercase roman numerals: `i', `ii', &hellip;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\roman</literal></term>
          <listitem>
            <para>uses uppercase roman numerals: `I', `II', &hellip;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\fnsymbol</literal></term>
          <listitem>
            <para>prints the value of <replaceable>counter</replaceable> in a specific sequence of nine
symbols (conventionally used for labeling footnotes).  The value of
<replaceable>counter</replaceable> must be between&#xa0;1 and&#xa0;9, inclusive.</para>
            <para>The symbols mostly aren't supported in Info, but here are the names:<literallayout>
asterix(*) dagger ddagger section-sign paragraph-sign parallel
double-asterix(**) double-dagger double-ddagger
</literallayout></para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="11.2" id="\usecounter">
      <title><literal>\usecounter{<replaceable>counter</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\usecounter</primary></indexterm><indexterm role="cp"><primary>list items, specifying counter</primary></indexterm><indexterm role="cp"><primary>numbered items, specifying counter</primary></indexterm>
Synopsis:</para>
      <screen>
\usecounter{<replaceable>counter</replaceable>}
</screen>
      <para>The <literal>\usecounter</literal> command is used in the second argument of the
<literal>list</literal> environment to specify <replaceable>counter</replaceable> to be used to number
the list items.</para>
    </sect1>

    <sect1 label="11.3" id="\value">
      <title><literal>\value{<replaceable>counter</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\value</primary></indexterm><indexterm role="cp"><primary>counters, getting value of</primary></indexterm>
Synopsis:</para>
      <screen>
\value{<replaceable>counter</replaceable>}
</screen>
      <para>The <literal>\value</literal> command produces the value of <replaceable>counter</replaceable>.  It can
be used anywhere &latex; expects a number, for example:</para>
      <screen>
\setcounter{myctr}{3}
\addtocounter{myctr}{1}
\hspace{\value{myctr}\parindent}
</screen>
    </sect1>

    <sect1 label="11.4" id="\setcounter">
      <title><literal>\setcounter{<replaceable>counter</replaceable>}{<replaceable>value</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\setcounter</primary></indexterm><indexterm role="cp"><primary>counters, setting</primary></indexterm><indexterm role="cp"><primary>setting counters</primary></indexterm>
Synopsis:</para>
      <screen>
\setcounter{<replaceable>\counter</replaceable>}{<replaceable>value</replaceable>}
</screen>
      <para>The <literal>\setcounter</literal> command sets the value of <replaceable>\counter</replaceable> to the
<replaceable>value</replaceable> argument.</para>
    </sect1>

    <sect1 label="11.5" id="\addtocounter">
      <title><literal>\addtocounter{<replaceable>counter</replaceable>}{<replaceable>value</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\addtocounter</primary></indexterm>
The <literal>\addtocounter</literal> command increments <replaceable>counter</replaceable> by the
amount specified by the <replaceable>value</replaceable> argument, which may be negative.</para>
    </sect1>

    <sect1 label="11.6" id="\refstepcounter">
      <title><literal>\refstepcounter{<replaceable>counter</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\refstepcounter</primary></indexterm>
The <literal>\refstepcounter</literal> command works in the same way as
<literal>\stepcounter</literal> See <xref linkend="\stepcounter"></xref>, except it also defines the
current <literal>\ref</literal> value to be the result of <literal>\thecounter</literal>.</para>
    </sect1>

    <sect1 label="11.7" id="\stepcounter">
      <title><literal>\stepcounter{<replaceable>counter</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\stepcounter</primary></indexterm>
The <literal>\stepcounter</literal> command adds one to <replaceable>counter</replaceable> and
resets all subsidiary counters.</para>
    </sect1>

    <sect1 label="11.8" id="\day-\month-\year">
      <title><literal>\day \month \year</literal>: Predefined counters</title>
      <para><indexterm role="fn"><primary>\day</primary></indexterm><indexterm role="fn"><primary>\month</primary></indexterm><indexterm role="fn"><primary>\year</primary></indexterm>
&latex; defines counters for the day of the month (<literal>\day</literal>,
1&ndash;31), month of the year (<literal>\month</literal>, 1&ndash;12), and year
(<literal>\year</literal>, Common Era).  When &tex; starts up, they are
set to the current values on the system where &tex; is running.  They
are not updated as the job progresses.</para>
      <para>The related command <literal>\today</literal> produces a string representing the
current day (see <xref linkend="\today"></xref>).</para>
    </sect1>
  </chapter>

  <chapter label="12" id="Lengths">
    <title>Lengths</title>
    <para><indexterm role="cp"><primary>lengths, defining and using</primary></indexterm>
A <literal>length</literal> is a measure of distance.  Many &latex; commands take a
length as an argument.</para>

    <sect1 label="12.1" id="\setlength">
      <title><literal>\setlength{\<replaceable>len</replaceable>}{<replaceable>value</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\setlength</primary></indexterm><indexterm role="cp"><primary>lengths, setting</primary></indexterm>
The <literal>\setlength</literal> sets the value of <replaceable>\len</replaceable> to the <replaceable>value</replaceable>
argument, which can be expressed in any units that &latex;
understands, i.e., inches (<literal>in</literal>), millimeters (<literal>mm</literal>), points
(<literal>pt</literal>), big points (<literal>bp</literal>, etc.</para>
    </sect1>

    <sect1 label="12.2" id="\addtolength">
      <title>\addtolength{<replaceable>\len</replaceable>}{<replaceable>amount</replaceable>}</title>
      <para><indexterm role="fn"><primary>\addtolength</primary></indexterm><indexterm role="cp"><primary>lengths, adding to</primary></indexterm>
The <literal>\addtolength</literal> command increments a &ldquo;length command&rdquo;
<replaceable>\len</replaceable> by the amount specified in the <replaceable>amount</replaceable> argument, which
may be negative.</para>
    </sect1>

    <sect1 label="12.3" id="\settodepth">
      <title><literal>\settodepth</literal></title>
      <para><indexterm role="fn"><primary>\settodepth</primary></indexterm>
<literal>\settodepth{\gnat}{text}</literal></para>
      <para>The <literal>\settodepth</literal> command sets the value of a <literal>length</literal> command
equal to the depth of the <literal>text</literal> argument.</para>
    </sect1>

    <sect1 label="12.4" id="\settoheight">
      <title><literal>\settoheight</literal></title>
      <para><indexterm role="fn"><primary>\settoheight</primary></indexterm>
<literal>\settoheight{\gnat}{text}</literal></para>
      <para>The <literal>\settoheight</literal> command sets the value of a <literal>length</literal> command
equal to the height of the <literal>text</literal> argument.</para>
    </sect1>

    <sect1 label="12.5" id="\settowidth">
      <title><literal>\settowidth{\<replaceable>len</replaceable>}{<replaceable>text</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\settowidth</primary></indexterm>
The <literal>\settowidth</literal> command sets the value of the command <replaceable>\len</replaceable>
to the width of the <replaceable>text</replaceable> argument.</para>
    </sect1>

    <sect1 label="12.6" id="Predefined-lengths">
      <title>Predefined lengths</title>
      <para><indexterm role="cp"><primary>lengths, predefined</primary></indexterm><indexterm role="cp"><primary>predefined lengths</primary></indexterm>
<literal>\width</literal>
<indexterm role="fn"><primary>\width</primary></indexterm>
<literal>\height</literal>
<indexterm role="fn"><primary>\height</primary></indexterm>
<literal>\depth</literal>
<indexterm role="fn"><primary>\depth</primary></indexterm>
<literal>\totalheight</literal>
<indexterm role="fn"><primary>\totalheight</primary></indexterm>
These length parameters can be used in the arguments of the box-making
commands (see <xref linkend="Boxes"></xref>). They specify the natural width etc. of the
text in the box. <literal>\totalheight</literal> equals <literal>\height</literal> +
<literal>\depth</literal>. To make a box with the text stretched to double the
natural size, e.g., say</para>
      <para><literal>\makebox[2\width]{Get a stretcher}</literal></para>
    </sect1>
  </chapter>

  <chapter label="13" id="Line-breaking">
    <title>Line breaking</title>
    <para><indexterm role="cp"><primary>line breaking</primary></indexterm><indexterm role="cp"><primary>breaking lines</primary></indexterm>
The first thing &latex; does when processing ordinary text is to
translate your input file into a sequence of glyphs and spaces.  To
produce a printed document, this sequence must be broken into lines
(and these lines must be broken into pages).</para>
    <para>&latex; usually does the line (and page) breaking for you, but in
some environments, you do the line breaking yourself with the
<literal>\\</literal> command, and you can always manually force breaks.</para>

    <sect1 label="13.1" id="\\">
      <title><literal>\\</literal>[*][<replaceable>morespace</replaceable>]</title>
      <para><indexterm role="fn"><primary>\\ force line break</primary></indexterm><indexterm role="cp"><primary>new line, starting</primary></indexterm><indexterm role="cp"><primary>line break, forcing</primary></indexterm>
The <literal>\\</literal> command tells &latex; to start a new line.  It has an
optional argument, <replaceable>morespace</replaceable>, that specifies how much extra
vertical space is to be inserted before the next line.  This can be a
negative amount.</para>
      <para>The <literal>\\*</literal> command is the same as the ordinary <literal>\\</literal> command
except that it tells &latex; not to start a new page after the line.</para>
    </sect1>

    <sect1 label="13.2" id="\obeycr-&-\restorecr">
      <title><literal>\obeycr</literal> &amp; <literal>\restorecr</literal></title>
      <para><indexterm role="fn"><primary>\obeycr</primary></indexterm><indexterm role="fn"><primary>\restorecr</primary></indexterm><indexterm role="cp"><primary>new line, output as input</primary></indexterm>
The <literal>\obeycr</literal> command makes a return in the input file
(&lsquo;<literal>^^M</literal>&rsquo;, internally) the same as <literal>\\</literal> (followed by
<literal>\relax</literal>).  So each new line in the input will also be a new line
in the output.</para>
      <para><literal>\restorecr</literal> restores normal line-breaking behavior.</para>
    </sect1>

    <sect1 label="13.3" id="\newline">
      <title><literal>\newline</literal></title>
      <para><indexterm role="fn"><primary>\newline</primary></indexterm><indexterm role="cp"><primary>new line, starting (paragraph mode)</primary></indexterm>
The <literal>\newline</literal> command breaks the line at the present point, with
no stretching of the text before it.  It can only be used in paragraph
mode.</para>
    </sect1>

    <sect1 label="13.4" id="\--(hyphenation)">
      <title><literal>\-</literal> (discretionary hyphen)</title>
      <para><indexterm role="fn"><primary>\- (hyphenation)</primary></indexterm><indexterm role="cp"><primary>hyphenation, forcing</primary></indexterm>
The <literal>\-</literal> command tells &latex; that it may hyphenate the word at
that point.  &latex; is very good at hyphenating, and it will usually
find most of the correct hyphenation points, and almost never use an
incorrect one.  The <literal>\-</literal> command is used for the exceptional
cases.</para>
      <para>When you insert <literal>\-</literal> commands in a word, the word will only be
hyphenated at those points and not at any of the hyphenation points
that &latex; might otherwise have chosen.</para>
    </sect1>

    <sect1 label="13.5" id="\fussy">
      <title><literal>\fussy</literal></title>
      <para><indexterm role="fn"><primary>\fussy</primary></indexterm>
The declaration <literal>\fussy</literal> (which is the default) makes &tex;
picky about line breaking.  This usually avoids too much space between
words, at the cost of an occasional overfull box.</para>
      <para>This command cancels the effect of a previous <literal>\sloppy</literal> command
(see <xref linkend="\sloppy"></xref>.</para>
    </sect1>

    <sect1 label="13.6" id="\sloppy">
      <title><literal>\sloppy</literal></title>
      <para>The declaration <literal>\sloppy</literal> makes &tex; less fussy about line
breaking. This will avoid overfull boxes, at the cost of loose
interword spacing.</para>
      <para>Lasts until a <literal>\fussy</literal> command is issued (see <xref linkend="\fussy"></xref>).</para>
    </sect1>

    <sect1 label="13.7" id="\hyphenation">
      <title><literal>\hyphenation</literal></title>
      <para><indexterm role="fn"><primary>\hyphenation</primary></indexterm><indexterm role="cp"><primary>hyphenation, defining</primary></indexterm>
Synopsis:</para>
      <screen>
\hyphenation{<replaceable>word-one</replaceable> <replaceable>word-two</replaceable>}
</screen>
      <para>The <literal>\hyphenation</literal> command declares allowed hyphenation points
with a <literal>-</literal> character in the given words.  The words are separated
by spaces.  &tex; will only hyphenate if the word matches exactly, no
inflections are tried.  Multiple <literal>\hyphenation</literal> commands
accumulate.  Some examples (the default &tex; hyphenation patterns
misses the hyphenations in these words):</para>
      <screen>
\hyphenation{ap-pen-dix col-umns data-base data-bases}
</screen>
    </sect1>

    <sect1 label="13.8" id="\linebreak-&-\nolinebreak">
      <title><literal>\linebreak</literal> &amp; <literal>\nolinebreak</literal></title>
      <para><indexterm role="fn"><primary>\linebreak</primary></indexterm><indexterm role="fn"><primary>\nolinebreak</primary></indexterm><indexterm role="cp"><primary>line breaks, forcing</primary></indexterm><indexterm role="cp"><primary>line breaks, preventing</primary></indexterm>
Synopses:</para>
      <screen>
\linebreak[<replaceable>priority</replaceable>]
\nolinebreak[<replaceable>priority</replaceable>]
</screen>
      <para>By default, the <literal>\linebreak</literal> (<literal>\nolinebreak</literal>) command forces
(prevents) a line break at the current position.  For
<literal>\linebreak</literal>, the spaces in the line are stretched out so that it
extends to the right margin as usual.</para>
      <para>With the optional argument <replaceable>priority</replaceable>, you can convert the command
from a demand to a request.  The <replaceable>priority</replaceable> must be a number from
0 to&#xa0;4.  The higher the number, the more insistent the request.</para>
    </sect1>
  </chapter>

  <chapter label="14" id="Page-breaking">
    <title>Page breaking</title>
    <para><indexterm role="cp"><primary>page breaking</primary></indexterm><indexterm role="cp"><primary>breaking pages</primary></indexterm>
&latex; starts new pages asynchronously, when enough material has
accumulated to fill up a page.  Usually this happens automatically,
but sometimes you may want to influence the breaks.</para>

    <sect1 label="14.1" id="\cleardoublepage">
      <title><literal>\cleardoublepage</literal></title>
      <para><indexterm role="fn"><primary>\cleardoublepage</primary></indexterm><indexterm role="cp"><primary>starting on a right-hand page</primary></indexterm>
The <literal>\cleardoublepage</literal> command ends the current page and causes all
figures and tables that have so far appeared in the input to be printed.
In a two-sided printing style, it also makes the next page a right-hand
(odd-numbered) page, producing a blank page if necessary.</para>
    </sect1>

    <sect1 label="14.2" id="\clearpage">
      <title><literal>\clearpage</literal></title>
      <para><indexterm role="fn"><primary>\clearpage</primary></indexterm><indexterm role="cp"><primary>flushing floats and starting a page</primary></indexterm><indexterm role="cp"><primary>starting a new page and clearing floats</primary></indexterm>
The <literal>\clearpage</literal> command ends the current page and causes all
figures and tables that have so far appeared in the input to be printed.</para>
    </sect1>

    <sect1 label="14.3" id="\newpage">
      <title><literal>\newpage</literal></title>
      <para><indexterm role="fn"><primary>\newpage</primary></indexterm><indexterm role="cp"><primary>new page, starting</primary></indexterm><indexterm role="cp"><primary>starting a new page</primary></indexterm>
The <literal>\newpage</literal> command ends the current page, but does not clear
floats (see <literal>\clearpage</literal> above).</para>
    </sect1>

    <sect1 label="14.4" id="\enlargethispage">
      <title><literal>\enlargethispage</literal></title>
      <para><indexterm role="fn"><primary>\enlargethispage</primary></indexterm><indexterm role="cp"><primary>enlarge current page</primary></indexterm>
<literal>\enlargethispage{size}</literal></para>
      <para><literal>\enlargethispage*{size}</literal></para>
      <para>Enlarge the <literal>\textheight</literal> for the current page by the specified
amount; e.g. <literal>\enlargethispage{\baselineskip}</literal> will allow one
additional line.</para>
      <para>The starred form tries to squeeze the material together on the page as
much as possible. This is normally used together with an explicit
<literal>\pagebreak</literal>.</para>
    </sect1>

    <sect1 label="14.5" id="\pagebreak-&-\nopagebreak">
      <title><literal>\pagebreak</literal> &amp; <literal>\nopagebreak</literal></title>
      <para><indexterm role="fn"><primary>\pagebreak</primary></indexterm><indexterm role="fn"><primary>\nopagebreak</primary></indexterm><indexterm role="cp"><primary>page break, forcing</primary></indexterm><indexterm role="cp"><primary>page break, preventing</primary></indexterm>
Synopses:</para>
      <screen>
\pagebreak[<replaceable>priority</replaceable>]
\nopagebreak[<replaceable>priority</replaceable>]
</screen>
      <para>By default, the <literal>\pagebreak</literal> (<literal>\nopagebreak</literal>) command forces
(prevents) a page break at the current position.  For
<literal>\linebreak</literal>, the vertical space on the page is stretched out
where possible so that it extends to the normal bottom margin.</para>
      <para>With the optional argument <replaceable>priority</replaceable>, you can convert the
<literal>\pagebreak</literal> command from a demand to a request.  The number must
be a number from 0 to&#xa0;4.  The higher the number, the more
insistent the request is.</para>
    </sect1>
  </chapter>

  <chapter label="15" id="Making-paragraphs">
    <title>Making paragraphs</title>
    <para><indexterm role="cp"><primary>making paragraphs</primary></indexterm><indexterm role="cp"><primary>paragraphs</primary></indexterm>
A paragraph is ended by one or more completely blank lines&mdash;lines not
containing even a <literal>%</literal>.  A blank line should not appear where a new
paragraph cannot be started, such as in math mode or in the argument of
a sectioning command.</para>

    <sect1 label="15.1" id="\indent">
      <title><literal>\indent</literal></title>
      <para><indexterm role="fn"><primary>\indent</primary></indexterm><indexterm role="fn"><primary>\parindent</primary></indexterm><indexterm role="cp"><primary>indent, forcing</primary></indexterm>
<literal>\indent</literal> produces a horizontal space whose width equals the
width of the <literal>\parindent</literal> length, the normal paragraph
indentation.  It is used to add paragraph indentation where it would
otherwise be suppressed.</para>
      <para>The default value for <literal>\parindent</literal> is <literal>1em</literal> in two-column
mode, otherwise <literal>15pt</literal> for <literal>10pt</literal> documents, <literal>17pt</literal> for
<literal>11pt</literal>, and <literal>1.5em</literal> for <literal>12pt</literal>.</para>
    </sect1>

    <sect1 label="15.2" id="\noindent">
      <title><literal>\noindent</literal></title>
      <para><indexterm role="fn"><primary>\noindent</primary></indexterm><indexterm role="cp"><primary>indent, suppressing</primary></indexterm>
When used at the beginning of the paragraph, <literal>\noindent</literal>
suppresses any paragraph indentation.  It has no effect when used in
the middle of a paragraph.</para>
    </sect1>

    <sect1 label="15.3" id="\parskip">
      <title><literal>\parskip</literal></title>
      <para><indexterm role="fn"><primary>\parskip</primary></indexterm><indexterm role="cp"><primary>vertical space before paragraphs</primary></indexterm>
<literal>\parskip</literal> is a rubber length defining extra vertical space added
before each paragraph.  The default is <literal>0pt plus1pt</literal>.</para>
    </sect1>

    <sect1 label="15.4" id="Marginal-notes">
      <title>Marginal notes</title>
      <para><indexterm role="cp"><primary>marginal notes</primary></indexterm><indexterm role="cp"><primary>notes in the margin</primary></indexterm><indexterm role="cp"><primary>remarks in the margin</primary></indexterm><indexterm role="fn"><primary>\marginpar</primary></indexterm>
Synopsis:</para>
      <screen>
\marginpar[<replaceable>left</replaceable>]{<replaceable>right</replaceable>}
</screen>
      <para>The <literal>\marginpar</literal> command creates a note in the margin.  The first
line of the note will have the same baseline as the line in the text
where the <literal>\marginpar</literal> occurs.</para>
      <para>When you only specify the mandatory argument <replaceable>right</replaceable>, the text
will be placed</para>
      <itemizedlist mark="bullet">
        <listitem>
          <para>in the right margin for one-sided layout;</para>
        </listitem>
        <listitem>
          <para>in the outside margin for two-sided layout;</para>
        </listitem>
        <listitem>
          <para>in the nearest margin for two-column layout.</para>
        </listitem>
      </itemizedlist>
      <para><indexterm role="fn"><primary>\reversemarginpar</primary></indexterm><indexterm role="fn"><primary>\normalmarginpar</primary></indexterm>The command <literal>\reversemarginpar</literal> places subsequent marginal notes
in the opposite (inside) margin.  <literal>\normalmarginpar</literal> places them
in the default position.</para>
      <para>When you specify both arguments, <replaceable>left</replaceable> is used for the left
margin, and <replaceable>right</replaceable> is used for the right margin.</para>
      <para>The first word will normally not be hyphenated; you can enable
hyphenation there by beginning the node with <literal>\hspace{0pt}</literal>.</para>
      <para>These parameters affect the formatting of the note:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\marginparpush</literal></term>
          <listitem>
            <para>Minimum vertical space between notes; default &lsquo;<literal>7pt</literal>&rsquo; for
&lsquo;<literal>12pt</literal>&rsquo; documents, &lsquo;<literal>5pt</literal>&rsquo; else.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\marginparsep</literal></term>
          <listitem>
            <para>Horizontal space between the main text and the note; default
&lsquo;<literal>11pt</literal>&rsquo; for &lsquo;<literal>10pt</literal>&rsquo; documents, &lsquo;<literal>10pt</literal>&rsquo; else.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\marginparwidth</literal></term>
          <listitem>
            <para>Width of the note itself; default for a one-sided &lsquo;<literal>10pt</literal>&rsquo; document
is &lsquo;<literal>90pt</literal>&rsquo;, &lsquo;<literal>83pt</literal>&rsquo; for &lsquo;<literal>11pt</literal>&rsquo;, and &lsquo;<literal>68pt</literal>&rsquo; for
&lsquo;<literal>12pt</literal>&rsquo;; &lsquo;<literal>17pt</literal>&rsquo; more in each case for a two-sided document.
In two column mode, the default is &lsquo;<literal>48pt</literal>&rsquo;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>
  </chapter>

  <chapter label="16" id="Math-formulas">
    <title>Math formulas</title>
    <para><indexterm role="cp"><primary>math formulas</primary></indexterm><indexterm role="cp"><primary>formulas, math</primary></indexterm><indexterm role="cp"><primary>math mode, entering</primary></indexterm>
<indexterm role="fn"><primary>math environment</primary></indexterm><indexterm role="fn"><primary>displaymath environment</primary></indexterm><indexterm role="fn"><primary>equation environment</primary></indexterm>There are three environments that put &latex; in math mode:</para>
    <variablelist>
      <varlistentry>
        <term><literal>math</literal></term>
        <listitem>
          <para>For formulas that appear right in the text.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term><literal>displaymath</literal></term>
        <listitem>
          <para>For formulas that appear on their own line.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term><literal>equation</literal></term>
        <listitem>
          <para>The same as the displaymath environment except that it adds an equation
number in the right margin.</para>
        </listitem>
      </varlistentry>
    </variablelist>
    <para><indexterm role="fn"><primary>\(</primary></indexterm><indexterm role="fn"><primary>\)</primary></indexterm><indexterm role="fn"><primary>\[</primary></indexterm><indexterm role="fn"><primary>\]</primary></indexterm>The <literal>math</literal> environment can be used in both paragraph and LR mode,
but the <literal>displaymath</literal> and <literal>equation</literal> environments can be used
only in paragraph mode.  The <literal>math</literal> and <literal>displaymath</literal>
environments are used so often that they have the following short forms:</para>
    <screen>
\(...\)   <lineannotation>instead of</lineannotation>   \begin{math}...\end{math}
\[...\]   <lineannotation>instead of</lineannotation>   \begin{displaymath}...\end{displaymath}
</screen>
    <para><indexterm role="fn"><primary>$</primary></indexterm>In fact, the <literal>math</literal> environment is so common that it has an even
shorter form:</para>
    <screen>
$ ... $   <lineannotation>instead of</lineannotation>   \(...\)
</screen>
    <para><indexterm role="fn"><primary>\boldmath</primary></indexterm><indexterm role="fn"><primary>\unboldmath</primary></indexterm>The <literal>\boldmath</literal> command changes math letters and symbols to be in
a bold font.  It is used <emphasis>outside</emphasis> of math mode.  Conversely, the
<literal>\unboldmath</literal> command changes math glyphs to be in a normal font;
it too is used <emphasis>outside</emphasis> of math mode.</para>
<!-- xx own section? Math fonts? -->
    <para><indexterm role="fn"><primary>\displaystyle</primary></indexterm>The <literal>\displaystyle</literal> declaration forces the size and style of the
formula to be that of <literal>displaymath</literal>, e.g., with limits above and
below summations.  For example</para>
    <screen>
$\displaystyle \sum_{n=0}^\infty x_n $
</screen>
<!-- xx see also \cal, \mathcal -->
    <sect1 label="16.1" id="Subscripts-&-Superscripts">
      <title>Subscripts &amp; Superscripts</title>
      <para><indexterm role="cp"><primary>superscript</primary></indexterm><indexterm role="cp"><primary>subscript</primary></indexterm><indexterm role="cp"><primary>exponent</primary></indexterm><indexterm role="fn"><primary>_</primary></indexterm><indexterm role="fn"><primary>^</primary></indexterm>
To get an expression <wordasword>exp</wordasword> to appear as a subscript, you just type
<literal>_{</literal><wordasword>exp</wordasword><literal>}</literal>.  To get <wordasword>exp</wordasword> to appear as a
superscript, you type <literal>^{</literal><wordasword>exp</wordasword><literal>}</literal>. &latex; handles
superscripted superscripts and all of that stuff in the natural way.
It even does the right thing when something has both a subscript and a
superscript.</para>
    </sect1>

    <sect1 label="16.2" id="Math-symbols">
      <title>Math symbols</title>
      <para><indexterm role="cp"><primary>math symbols</primary></indexterm><indexterm role="cp"><primary>symbols, math</primary></indexterm><indexterm role="cp"><primary>greek letters</primary></indexterm>
&latex; provides almost any mathematical symbol you're likely to
need. The commands for generating them can be used only in math mode.
For example, if you include <literal>$\pi$</literal> in your source, you will get
the pi symbol (\pi) in your output.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\|</literal></term>
          <listitem>
            <para>\|</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\aleph</literal></term>
          <listitem>
            <para>\aleph</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\alpha</literal></term>
          <listitem>
            <para>\alpha</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\amalg</literal></term>
          <listitem>
            <para>\amalg (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\angle</literal></term>
          <listitem>
            <para>\angle</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\approx</literal></term>
          <listitem>
            <para>\approx (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ast</literal></term>
          <listitem>
            <para>\ast (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\asymp</literal></term>
          <listitem>
            <para>\asymp (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\backslash</literal></term>
          <listitem>
            <para>\ (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\beta</literal></term>
          <listitem>
            <para>\beta</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigcap</literal></term>
          <listitem>
            <para>\bigcap</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigcirc</literal></term>
          <listitem>
            <para>\bigcirc (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigcup</literal></term>
          <listitem>
            <para>\bigcup</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigodot</literal></term>
          <listitem>
            <para>\bigodot</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigoplus</literal></term>
          <listitem>
            <para>\bigoplus</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigotimes</literal></term>
          <listitem>
            <para>\bigotimes</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigtriangledown</literal></term>
          <listitem>
            <para>\bigtriangledown (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigtriangleup</literal></term>
          <listitem>
            <para>\bigtriangleup (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigsqcup</literal></term>
          <listitem>
            <para>\bigsqcup</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\biguplus</literal></term>
          <listitem>
            <para>\biguplus</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigcap</literal></term>
          <listitem>
            <para>\bigvee</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bigwedge</literal></term>
          <listitem>
            <para>\bigwedge</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bot</literal></term>
          <listitem>
            <para>\bot</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bowtie</literal></term>
          <listitem>
            <para>\bowtie (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Box</literal></term>
          <listitem>
            <para>(square open box symbol) 
<!-- xx not in plain --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bullet</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>bullet symbol</primary></indexterm>\bullet (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cap</literal></term>
          <listitem>
            <para>\cap (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cdot</literal></term>
          <listitem>
            <para>\cdot (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\chi</literal></term>
          <listitem>
            <para>\chi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\circ</literal></term>
          <listitem>
            <para>\circ (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\clubsuit</literal></term>
          <listitem>
            <para>\clubsuit</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cong</literal></term>
          <listitem>
            <para>\cong (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\coprod</literal></term>
          <listitem>
            <para>\coprod</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cup</literal></term>
          <listitem>
            <para>\cup (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dagger</literal></term>
          <listitem>
            <para>\dagger (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dashv</literal></term>
          <listitem>
            <para>\dashv (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ddagger</literal></term>
          <listitem>
            <para>\dagger (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Delta</literal></term>
          <listitem>
            <para>\Delta</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\delta</literal></term>
          <listitem>
            <para>\delta</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Diamond</literal></term>
          <listitem>
            <para>bigger \diamond 
<!-- xx not in plain --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\diamond</literal></term>
          <listitem>
            <para>\diamond (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\diamondsuit</literal></term>
          <listitem>
            <para>\diamondsuit</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\div</literal></term>
          <listitem>
            <para>\div (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\doteq</literal></term>
          <listitem>
            <para>\doteq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\downarrow</literal></term>
          <listitem>
            <para>\downarrow (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Downarrow</literal></term>
          <listitem>
            <para>\Downarrow (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ell</literal></term>
          <listitem>
            <para>\ell</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\emptyset</literal></term>
          <listitem>
            <para>\emptyset</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\epsilon</literal></term>
          <listitem>
            <para>\epsilon</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\equiv</literal></term>
          <listitem>
            <para>\equiv (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\eta</literal></term>
          <listitem>
            <para>\eta</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\exists</literal></term>
          <listitem>
            <para>\exists</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\flat</literal></term>
          <listitem>
            <para>\flat</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\forall</literal></term>
          <listitem>
            <para>\forall</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\frown</literal></term>
          <listitem>
            <para>\frown (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Gamma</literal></term>
          <listitem>
            <para>\Gamma</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\gamma</literal></term>
          <listitem>
            <para>\gamma</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ge</literal></term>
          <listitem>
            <para>\ge</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\geq</literal></term>
          <listitem>
            <para>\geq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\gets</literal></term>
          <listitem>
            <para>\gets</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\gg</literal></term>
          <listitem>
            <para>\gg (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\hbar</literal></term>
          <listitem>
            <para>\hbar</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\heartsuit</literal></term>
          <listitem>
            <para>\heartsuit</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\hookleftarrow</literal></term>
          <listitem>
            <para>\hookleftarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\hookrightarrow</literal></term>
          <listitem>
            <para>\hookrightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\iff</literal></term>
          <listitem>
            <para>\iff</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Im</literal></term>
          <listitem>
            <para>\Im</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\in</literal></term>
          <listitem>
            <para>\in (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\infty</literal></term>
          <listitem>
            <para>\infty</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\int</literal></term>
          <listitem>
            <para>\int</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\iota</literal></term>
          <listitem>
            <para>\iota</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Join</literal></term>
          <listitem>
            <para>condensed bowtie symbol (relation) 
<!-- xx not in plain --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\kappa</literal></term>
          <listitem>
            <para>\kappa</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Lambda</literal></term>
          <listitem>
            <para>\Lambda</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lambda</literal></term>
          <listitem>
            <para>\lambda</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\land</literal></term>
          <listitem>
            <para>\land</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\langle</literal></term>
          <listitem>
            <para>\langle (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lbrace</literal></term>
          <listitem>
            <para>\lbrace (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lbrack</literal></term>
          <listitem>
            <para>\lbrack (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lceil</literal></term>
          <listitem>
            <para>\lceil (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\le</literal></term>
          <listitem>
            <para>\le</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\leadsto</literal></term>
<!-- xx missing from plain -->
          <listitem>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Leftarrow</literal></term>
          <listitem>
            <para>\Leftarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\leftarrow</literal></term>
          <listitem>
            <para>\leftarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\leftharpoondown</literal></term>
          <listitem>
            <para>\leftharpoondown</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\leftharpoonup</literal></term>
          <listitem>
            <para>\leftharpoonup</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Leftrightarrow</literal></term>
          <listitem>
            <para>\Leftrightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\leftrightarrow</literal></term>
          <listitem>
            <para>\leftrightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\leq</literal></term>
          <listitem>
            <para>\leq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lfloor</literal></term>
          <listitem>
            <para>\lfloor (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lhd</literal></term>
          <listitem>
            <para>(left-pointing arrow head) 
<!-- xx not in plain --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ll</literal></term>
          <listitem>
            <para>\ll (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lnot</literal></term>
          <listitem>
            <para>\lnot</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\longleftarrow</literal></term>
          <listitem>
            <para>\longleftarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\longleftrightarrow</literal></term>
          <listitem>
            <para>\longleftrightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\longmapsto</literal></term>
          <listitem>
            <para>\longmapsto</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\longrightarrow</literal></term>
          <listitem>
            <para>\longrightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lor</literal></term>
          <listitem>
            <para>\lor</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mapsto</literal></term>
          <listitem>
            <para>\mapsto</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mho</literal></term>
<!-- xx not in plain -->
          <listitem>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mid</literal></term>
          <listitem>
            <para>\mid (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\models</literal></term>
          <listitem>
            <para>\models (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mp</literal></term>
          <listitem>
            <para>\mp (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\mu</literal></term>
          <listitem>
            <para>\mu</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\nabla</literal></term>
          <listitem>
            <para>\nabla</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\natural</literal></term>
          <listitem>
            <para>\natural</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ne</literal></term>
          <listitem>
            <para>\ne</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\nearrow</literal></term>
          <listitem>
            <para>\nearrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\neg</literal></term>
          <listitem>
            <para>\neg</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\neq</literal></term>
          <listitem>
            <para>\neq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ni</literal></term>
          <listitem>
            <para>\ni (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\not</literal></term>
          <listitem>
            <para>Overstrike a following operator with a /, as in \not=.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\notin</literal></term>
          <listitem>
            <para>\ni</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\nu</literal></term>
          <listitem>
            <para>\nu</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\nwarrow</literal></term>
          <listitem>
            <para>\nwarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\odot</literal></term>
          <listitem>
            <para>\odot (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\oint</literal></term>
          <listitem>
            <para>\oint</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Omega</literal></term>
          <listitem>
            <para>\Omega</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\omega</literal></term>
          <listitem>
            <para>\omega</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ominus</literal></term>
          <listitem>
            <para>\ominus (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\oplus</literal></term>
          <listitem>
            <para>\oplus (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\oslash</literal></term>
          <listitem>
            <para>\oslash (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\otimes</literal></term>
          <listitem>
            <para>\otimes (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\owns</literal></term>
          <listitem>
            <para>\owns</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\parallel</literal></term>
          <listitem>
            <para>\parallel (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\partial</literal></term>
          <listitem>
            <para>\partial</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\perp</literal></term>
          <listitem>
            <para>\perp (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\phi</literal></term>
          <listitem>
            <para>\phi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Pi</literal></term>
          <listitem>
            <para>\Pi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\pi</literal></term>
          <listitem>
            <para>\pi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\pm</literal></term>
          <listitem>
            <para>\pm (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\prec</literal></term>
          <listitem>
            <para>\prec (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\preceq</literal></term>
          <listitem>
            <para>\preceq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\prime</literal></term>
          <listitem>
            <para>\prime</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\prod</literal></term>
          <listitem>
            <para>\prod</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\propto</literal></term>
          <listitem>
            <para>\propto (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Psi</literal></term>
          <listitem>
            <para>\Psi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\psi</literal></term>
          <listitem>
            <para>\psi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rangle</literal></term>
          <listitem>
            <para>\rangle (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rbrace</literal></term>
          <listitem>
            <para>\rbrace (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rbrack</literal></term>
          <listitem>
            <para>\rbrack (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rceil</literal></term>
          <listitem>
            <para>\rceil (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Re</literal></term>
          <listitem>
            <para>\Re</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rfloor</literal></term>
          <listitem>
            <para>\rfloor</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rhd</literal></term>
          <listitem>
            <para>(binary operation) 
<!-- xx not in plain @math{\rhd} --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rho</literal></term>
          <listitem>
            <para>\rho</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Rightarrow</literal></term>
          <listitem>
            <para>\Rightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rightarrow</literal></term>
          <listitem>
            <para>\rightarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rightharpoondown</literal></term>
          <listitem>
            <para>\rightharpoondown</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rightharpoonup</literal></term>
          <listitem>
            <para>\rightharpoonup</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rightleftharpoons</literal></term>
          <listitem>
            <para>\rightleftharpoons</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\searrow</literal></term>
          <listitem>
            <para>\searrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\setminus</literal></term>
          <listitem>
            <para>\setminus (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sharp</literal></term>
          <listitem>
            <para>\sharp</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Sigma</literal></term>
          <listitem>
            <para>\Sigma</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sigma</literal></term>
          <listitem>
            <para>\sigma</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sim</literal></term>
          <listitem>
            <para>\sim (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\simeq</literal></term>
          <listitem>
            <para>\simeq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\smallint</literal></term>
          <listitem>
            <para>\smallint</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\smile</literal></term>
          <listitem>
            <para>\smile (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\spadesuit</literal></term>
          <listitem>
            <para>\spadesuit</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqcap</literal></term>
          <listitem>
            <para>\sqcap (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqcup</literal></term>
          <listitem>
            <para>\sqcup (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqsubset</literal></term>
          <listitem>
            <para>(relation) 
<!-- not in plain (@math{\sqsubset}) --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqsubseteq</literal></term>
          <listitem>
            <para>\sqsubseteq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqsupset</literal></term>
          <listitem>
            <para>(relation) 
<!-- not in plain (@math{\sqsupset}) --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqsupseteq</literal></term>
          <listitem>
            <para>\sqsupseteq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\star</literal></term>
          <listitem>
            <para>\star (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\subset</literal></term>
          <listitem>
            <para>\subset (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\subseteq</literal></term>
          <listitem>
            <para>\subseteq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\succ</literal></term>
          <listitem>
            <para>\succ (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\succeq</literal></term>
          <listitem>
            <para>\succeq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sum</literal></term>
          <listitem>
            <para>\sum</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\supset</literal></term>
          <listitem>
            <para>\supset (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\supseteq</literal></term>
          <listitem>
            <para>\supseteq (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\surd</literal></term>
          <listitem>
            <para>\surd</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\swarrow</literal></term>
          <listitem>
            <para>\swarrow</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tau</literal></term>
          <listitem>
            <para>\tau</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\theta</literal></term>
          <listitem>
            <para>\theta</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\times</literal></term>
          <listitem>
            <para>\times (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\to</literal></term>
          <listitem>
            <para>\to</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\top</literal></term>
          <listitem>
            <para>\top</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\triangle</literal></term>
          <listitem>
            <para>\triangle</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\triangleleft</literal></term>
          <listitem>
            <para>\triangleleft (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\triangleright</literal></term>
          <listitem>
            <para>\triangleright (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\unlhd</literal></term>
          <listitem>
            <para>left-pointing arrowhead with line under (binary operation) 
<!-- not in plain --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\unrhd</literal></term>
          <listitem>
            <para>right-pointing arrowhead with line under (binary operation) 
<!-- not in plain --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Uparrow</literal></term>
          <listitem>
            <para>\Uparrow (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\uparrow</literal></term>
          <listitem>
            <para>\uparrow (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Updownarrow</literal></term>
          <listitem>
            <para>\Updownarrow (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\updownarrow</literal></term>
          <listitem>
            <para>\updownarrow (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\uplus</literal></term>
          <listitem>
            <para>\uplus (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Upsilon</literal></term>
          <listitem>
            <para>\Upsilon</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\upsilon</literal></term>
          <listitem>
            <para>\upsilon</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\varepsilon</literal></term>
          <listitem>
            <para>\varepsilon</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\varphi</literal></term>
          <listitem>
            <para>\varphi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\varpi</literal></term>
          <listitem>
            <para>\varpi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\varrho</literal></term>
          <listitem>
            <para>\varrho</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\varsigma</literal></term>
          <listitem>
            <para>\varsigma</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\vartheta</literal></term>
          <listitem>
            <para>\vartheta</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\vdash</literal></term>
          <listitem>
            <para>\vdash (relation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\vee</literal></term>
          <listitem>
            <para>\vee (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Vert</literal></term>
          <listitem>
            <para>\Vert (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\vert</literal></term>
          <listitem>
            <para>\vert (delimiter)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\wedge</literal></term>
          <listitem>
            <para>\wedge (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\wp</literal></term>
          <listitem>
            <para>\wp</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\wr</literal></term>
          <listitem>
            <para>\wr (binary operation)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Xi</literal></term>
          <listitem>
            <para>\Xi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\xi</literal></term>
          <listitem>
            <para>\xi</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\zeta</literal></term>
          <listitem>
            <para>\zeta</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="16.3" id="Math-functions">
      <title>Math functions</title>
      <para><indexterm role="cp"><primary>math functions</primary></indexterm><indexterm role="cp"><primary>functions, math</primary></indexterm>
These commands produce roman function names in math mode with proper
spacing.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\arccos</literal></term>
          <listitem>
            <para>\arccos</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\arcsin</literal></term>
          <listitem>
            <para>\arcsin</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\arctan</literal></term>
          <listitem>
            <para>\arctan</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\arg</literal></term>
          <listitem>
            <para>\arg</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bmod</literal></term>
          <listitem>
            <para>Binary modulo operator (x \bmod y)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cos</literal></term>
          <listitem>
            <para>\cos</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cosh</literal></term>
          <listitem>
            <para>\cosh</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cot</literal></term>
          <listitem>
            <para>\cos</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\coth</literal></term>
          <listitem>
            <para>\cosh</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\csc</literal></term>
          <listitem>
            <para>\csc</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\deg</literal></term>
          <listitem>
            <para>\deg</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\det</literal></term>
          <listitem>
            <para>\deg</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dim</literal></term>
          <listitem>
            <para>\dim</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\exp</literal></term>
          <listitem>
            <para>\exp</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\gcd</literal></term>
          <listitem>
            <para>\gcd</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\hom</literal></term>
          <listitem>
            <para>\hom</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\inf</literal></term>
          <listitem>
            <para>\inf</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ker</literal></term>
          <listitem>
            <para>\ker</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lg</literal></term>
          <listitem>
            <para>\lg</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lim</literal></term>
          <listitem>
            <para>\lim</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\liminf</literal></term>
          <listitem>
            <para>\liminf</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\limsup</literal></term>
          <listitem>
            <para>\limsup</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ln</literal></term>
          <listitem>
            <para>\ln</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\log</literal></term>
          <listitem>
            <para>\log</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\max</literal></term>
          <listitem>
            <para>\max</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\min</literal></term>
          <listitem>
            <para>\min</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\pmod</literal></term>
          <listitem>
            <para>parenthesized modulus, as in (\pmod 2^n - 1)</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\Pr</literal></term>
          <listitem>
            <para>\Pr</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sec</literal></term>
          <listitem>
            <para>\sec</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sin</literal></term>
          <listitem>
            <para>\sin</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sinh</literal></term>
          <listitem>
            <para>\sinh</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sup</literal></term>
          <listitem>
            <para>\sup</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tan</literal></term>
          <listitem>
            <para>\tan</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tanh</literal></term>
          <listitem>
            <para>\tanh</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="16.4" id="Math-accents">
      <title>Math accents</title>
      <para><indexterm role="cp"><primary>math accents</primary></indexterm><indexterm role="cp"><primary>accents, mathematical</primary></indexterm>
&latex; provides a variety of commands for producing accented letters
in math.  These are different from accents in normal text
(see <xref linkend="Accents"></xref>).</para>
      <variablelist>
        <varlistentry>
          <term><literal>\acute</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>acute accent, math</primary></indexterm>Math acute accent: \acutex.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\bar</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>bar-over accent, math</primary></indexterm><indexterm role="cp"><primary>macron accent, math</primary></indexterm>Math bar-over accent: \barx.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\breve</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>breve accent, math</primary></indexterm>Math breve accent: \brevex.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\check</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>check accent, math</primary></indexterm><indexterm role="cp"><primary>h&aacute;c&lt;ek accent, math</primary></indexterm>Math h&aacute;c&lt;ek (check) accent: \checkx.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ddot</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>double dot accent, math</primary></indexterm>Math dieresis accent: \ddotx.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dot</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>overdot accent, math</primary></indexterm><indexterm role="cp"><primary>dot over accent, math</primary></indexterm>Math dot accent: \dotx.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\grave</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>grave accent, math</primary></indexterm>Math grave accent: \gravex.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\hat</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>hat accent, math</primary></indexterm><indexterm role="cp"><primary>circumflex accent, math</primary></indexterm>Math hat (circumflex) accent: \hatx.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\imath</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>dotless i, math</primary></indexterm>Math dotless i.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\jmath</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>dotless j, math</primary></indexterm>Math dotless j.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\tilde</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>tilde accent, math</primary></indexterm>Math tilde accent: \tildex.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\vec</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>vector symbol, math</primary></indexterm>Math vector symbol: \vecx.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\widehat</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>wide hat accent, math</primary></indexterm>Math wide hat accent: \widehatx+y.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\widehat</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>wide tile accent, math</primary></indexterm>Math wide tilde accent: \widetildex+y.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="16.5" id="Spacing-in-math-mode">
      <title>Spacing in math mode</title>
      <para><indexterm role="cp"><primary>spacing within math mode</primary></indexterm><indexterm role="cp"><primary>math mode, spacing</primary></indexterm>
In a <literal>math</literal> environment, &latex; ignores the spaces you type and
puts in the spacing according to the normal rules for mathematics
texts.  If you want different spacing, &latex; provides the following
commands for use in math mode:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\;</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\;</primary></indexterm>A thick space (5\over18\,quad).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\:</literal></term>
          <term><literal>\&gt;</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\:</primary></indexterm><indexterm role="fn"><primary>\&gt;</primary></indexterm>Both of these produce a medium space (2\over9\,quad).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\,</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\,</primary></indexterm>A thin space (1\over6\,quad); not restricted to math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\!</literal></term>
          <listitem>
            <para>A negative thin space (-1\over6\,quad).</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="16.6" id="Math-Miscellany">
      <title>Math Miscellany</title>
      <para><indexterm role="cp"><primary>math Miscellany</primary></indexterm></para>
      <variablelist>
        <varlistentry>
          <term><literal>\*</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>discretionary multiplication</primary></indexterm><indexterm role="cp"><primary>multiplication symbol, discretionary line break</primary></indexterm>A &ldquo;discretionary&rdquo; multiplication symbol, at which a line break is
allowed.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\cdots</literal></term>
          <listitem>
            <para>A horizontal ellipsis with the dots raised to the center of the line.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ddots</literal></term>
          <listitem>
            <para>A diagonal ellipsis: \ddots.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\frac{num}{den}</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\frac</primary></indexterm>Produces the fraction <literal>num</literal> divided by <literal>den</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\left <replaceable>delim1</replaceable> ... \right <replaceable>delim2</replaceable></literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\right</primary></indexterm><indexterm role="cp"><primary>null delimiter</primary></indexterm>The two delimiters need not match; &lsquo;<literal>.</literal>&rsquo; acts as a null delimiter,
producing no output.  The delimiters are sized according to the math
in between.  Example: <literal>\left( \sum_i=1^10 a_i \right]</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\overbrace{<replaceable>text</replaceable>}</literal></term>
          <listitem>
            <para>Generates a brace over <replaceable>text</replaceable>.
For example, \overbracex+\cdots+x^k \rm\;times.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\overline{<replaceable>text</replaceable>}</literal></term>
          <listitem>
            <para>Generates a horizontal line over <replaceable>tex</replaceable>.
For exampe, \overlinex+y.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\sqrt[<replaceable>root</replaceable>]{arg}</literal></term>
          <listitem>
            <para>Produces the representation of the square root of <replaceable>arg</replaceable>.  The
optional argument <replaceable>root</replaceable> determines what root to produce.  For
example, the cube root of <literal>x+y</literal> would be typed as
<literal>$\sqrt[3]{x+y}$</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\stackrel{<replaceable>text</replaceable>}{<replaceable>relation</replaceable>}</literal></term>
          <listitem>
            <para>Puts <replaceable>text</replaceable> above <replaceable>relation</replaceable>.  For example,
<literal>\stackrel{f}{\longrightarrow}</literal>.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\underbrace{math}</literal></term>
          <listitem>
            <para>Generates <replaceable>math</replaceable> with a brace underneath.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\underline{text}</literal></term>
          <listitem>
            <para>Causes <replaceable>text</replaceable>, which may be either math mode or not, to be
underlined.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\vdots</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\vdots</primary></indexterm>Produces a vertical ellipsis.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>
  </chapter>

  <chapter label="17" id="Modes">
    <title>Modes</title>
    <para><indexterm role="cp"><primary>modes</primary></indexterm><indexterm role="cp"><primary>paragraph mode</primary></indexterm><indexterm role="cp"><primary>math mode</primary></indexterm><indexterm role="cp"><primary>left-to-right mode</primary></indexterm><indexterm role="cp"><primary>lR mode</primary></indexterm></para>
    <para>When &latex; is processing your input text, it is always in one of three
modes:</para>
    <itemizedlist mark="bullet">
      <listitem>
        <para>Paragraph mode</para>
      </listitem>
      <listitem>
        <para>Math mode</para>
      </listitem>
      <listitem>
        <para>Left-to-right mode, called LR mode for short</para>
      </listitem>
    </itemizedlist>
    <para>&latex; changes mode only when it goes up or down a staircase to a
different level, though not all level changes produce mode changes.
Mode changes occur only when entering or leaving an environment, or when
&latex; is processing the argument of certain text-producing commands.</para>
    <para>&ldquo;Paragraph mode&rdquo; is the most common; it's the one &latex; is in
when processing ordinary text.  In that mode, &latex; breaks your
text into lines and breaks the lines into pages.  &latex; is in
&ldquo;math mode&rdquo; when it's generating a mathematical formula.  In &ldquo;LR
mode&rdquo;, as in paragraph mode, &latex; considers the output that it
produces to be a string of words with spaces between them.  However,
unlike paragraph mode, &latex; keeps going from left to right; it
never starts a new line in LR mode.  Even if you put a hundred words
into an <literal>\mbox</literal>, &latex; would keep typesetting them from left
to right inside a single box, and then complain because the resulting
box was too wide to fit on the line.</para>
    <para>&latex; is in LR mode when it starts making a box with an <literal>\mbox</literal>
command.  You can get it to enter a different mode inside the box - for
example, you can make it enter math mode to put a formula in the box.
There are also several text-producing commands and environments for
making a box that put &latex; in paragraph mode.  The box make by one of
these commands or environments will be called a <literal>parbox</literal>.  When
&latex; is in paragraph mode while making a box, it is said to be in
&ldquo;inner paragraph mode&rdquo;.  Its normal paragraph mode, which it starts out
in, is called &ldquo;outer paragraph mode&rdquo;.</para>
  </chapter>

  <chapter label="18" id="Page-Styles">
    <title>Page Styles</title>
    <para><indexterm role="cp"><primary>styles, page</primary></indexterm><indexterm role="cp"><primary>page styles</primary></indexterm>
The <literal>\documentclass</literal> command determines the size and position of
the page's head and foot.  The page style determines what goes in them.</para>

    <sect1 label="18.1" id="\maketitle">
      <title><literal>\maketitle</literal></title>
      <para><indexterm role="cp"><primary>titles, making</primary></indexterm><indexterm role="fn"><primary>\maketitle</primary></indexterm>
The <literal>\maketitle</literal> command generates a title on a separate title
page&mdash;except in the <literal>article</literal> class, where the title is placed
at the top of the first page.  Information used to produce the title
is obtained from the following declarations:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\author{<replaceable>name</replaceable> \and <replaceable>name2</replaceable>}</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>author, for titlepage</primary></indexterm><indexterm role="fn"><primary>\\ for <literal>\author</literal></primary></indexterm><indexterm role="fn"><primary>\and for <literal>\author</literal></primary></indexterm>The <literal>\author</literal> command declares the document author(s), where the
argument is a list of authors separated by <literal>\and</literal> commands.  Use
<literal>\\</literal> to separate lines within a single author's entry&mdash;for
example, to give the author's institution or address.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\date{<replaceable>text</replaceable>}</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>date, for titlepage</primary></indexterm>The <literal>\date</literal> command declares <replaceable>text</replaceable> to be the document's
date.  With no <literal>\date</literal> command, the current date (see <xref linkend="\today"></xref>)
is used.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\thanks{<replaceable>text</replaceable>}</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>thanks, for titlepage</primary></indexterm><indexterm role="cp"><primary>credit footnote</primary></indexterm>The <literal>\thanks</literal> command produces a <literal>\footnote</literal> to the title,
usually used for credit acknowledgements.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\title{<replaceable>text</replaceable>}</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>title, for titlepage</primary></indexterm><indexterm role="fn"><primary>\\ for <literal>\title</literal></primary></indexterm>The <literal>\title</literal> command declares <replaceable>text</replaceable> to be the title of the
document.  Use <literal>\\</literal> to force a line break, as usual.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="18.2" id="\pagenumbering">
      <title><literal>\pagenumbering</literal></title>
      <para><indexterm role="fn"><primary>\pagenumbering</primary></indexterm><indexterm role="cp"><primary>page numbering style</primary></indexterm>
Synopsis:</para>
      <screen>
\pagenumbering{<replaceable>style</replaceable>}
</screen>
      <para>Specifies the style of page numbers, according to <replaceable>style</replaceable>:</para>
      <variablelist>
        <varlistentry>
          <term><literal>arabic</literal></term>
          <listitem>
            <para>arabic numerals</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>roman</literal></term>
          <listitem>
            <para>lowercase Roman numerals</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>Roman</literal></term>
          <listitem>
            <para>uppercase Roman numerals</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>alph</literal></term>
          <listitem>
            <para>lowercase letters</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>Alph</literal></term>
          <listitem>
            <para>uppercase letters</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="18.3" id="\pagestyle">
      <title><literal>\pagestyle</literal></title>
      <para><indexterm role="fn"><primary>\pagestyle</primary></indexterm><indexterm role="cp"><primary>header style</primary></indexterm><indexterm role="cp"><primary>footer style</primary></indexterm><indexterm role="cp"><primary>running header and footer style</primary></indexterm>
Synopsis:</para>
      <screen>
\pagestyle{<replaceable>style</replaceable>}
</screen>
      <para>The <literal>\pagestyle</literal> command specifies how the headers and footers
are typeset from the current page onwards.  Values for <replaceable>style</replaceable>:</para>
      <variablelist>
        <varlistentry>
          <term><literal>plain</literal></term>
          <listitem>
            <para>Just a plain page number.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>empty</literal></term>
          <listitem>
            <para>Empty headers and footers, e.g., no page numbers.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>headings</literal></term>
          <listitem>
            <para>Put running headers on each page.  The document style specifies what
goes in the headers.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>myheadings</literal></term>
          <listitem>
            <para>Custom headers, specified via the <literal>\markboth</literal> or the
<literal>\markright</literal> commands.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>Here are the descriptions of <literal>\markboth</literal> and <literal>\markright</literal>:</para>
      <variablelist>
        <varlistentry>
          <term><literal>\markboth{<replaceable>left</replaceable>}{<replaceable>right</replaceable>}</literal></term>
          <listitem>
            <para>Sets both the left and the right heading.  A &ldquo;left-hand heading&rdquo;
(<replaceable>left</replaceable>) is generated by the last <literal>\markboth</literal> command before
the end of the page, while a &ldquo;right-hand heading&rdquo; (<replaceable>right</replaceable> is
generated by the first <literal>\markboth</literal> or <literal>\markright</literal> that
comes on the page if there is one, otherwise by the last one before
the page.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\markright{<replaceable>right</replaceable>}</literal></term>
          <listitem>
            <para>Sets the right heading, leaving the left heading unchanged.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="18.4" id="\thispagestyle">
      <title><literal>\thispagestyle{<replaceable>style</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\thispagestyle</primary></indexterm>
The <literal>\thispagestyle</literal> command works in the same manner as the
<literal>\pagestyle</literal> command (see previous section) except that it
changes to <replaceable>style</replaceable> for the current page only.</para>
    </sect1>
  </chapter>

  <chapter label="19" id="Spaces">
    <title>Spaces</title>
    <para><indexterm role="cp"><primary>spaces</primary></indexterm>
&latex; has many ways to produce white (or filled) space.</para>
    <para>Another space-producing command is <literal>\,</literal> to produce a &ldquo;thin&rdquo;
space (usually 1/6quad).  It can be used in text mode, but is
more often useful in math mode  (see <xref linkend="Spacing-in-math-mode"></xref>).</para>

    <sect1 label="19.1" id="\hspace">
      <title><literal>\hspace</literal></title>
      <para><indexterm role="fn"><primary>\hspace</primary></indexterm>
Synopsis:</para>
      <screen>
\hspace[*]{<replaceable>length</replaceable>}
</screen>
      <para>The <literal>\hspace</literal> command adds horizontal space.  The <replaceable>length</replaceable>
argument can be expressed in any terms that &latex; understands:
points, inches, etc.  It is a rubber length.  You can add both
negative and positive space with an <literal>\hspace</literal> command; adding
negative space is like backspacing.</para>
      <para>&latex; normally removes horizontal space that comes at the beginning
or end of a line.  To preserve this space, use the optional <literal>*</literal>
form.</para>
    </sect1>

    <sect1 label="19.2" id="\hfill">
      <title><literal>\hfill</literal></title>
      <para><indexterm role="fn"><primary>\hfill</primary></indexterm>The <literal>\hfill</literal> fill command produces a &ldquo;rubber length&rdquo; which has
no natural space but can stretch or shrink horizontally as far as
needed.</para>
      <para><indexterm role="fn"><primary>\fill</primary></indexterm>The <literal>\fill</literal> parameter is the rubber length itself (technically,
the glue value &lsquo;<literal>0pt plus1fill</literal>&rsquo;); thus, <literal>\hspace\fill</literal> is
equivalent to <literal>\hfill</literal>.</para>
    </sect1>

    <sect1 label="19.3" id="\SPACE">
      <title><literal>\SPACE</literal></title>
      <para><indexterm role="fn"><primary>\SPACE</primary></indexterm><indexterm role="fn"><primary>\TAB</primary></indexterm><indexterm role="fn"><primary>\NEWLINE</primary></indexterm>
The <literal>\ </literal> (space) command produces a normal interword space.  It's
useful after punctuation which shouldn't end a sentence.  For example
<literal>Knuth's article in Proc.\ Amer.\ Math\. Soc.\ is fundamental</literal>.
It is also often used after control sequences, as in <literal>\TeX\ is a
nice system.</literal></para>
      <para>In normal circumstances, <literal>\</literal><keycap>tab</keycap> and <literal>\</literal><keycap>newline</keycap>
are equivalent to <literal>\ </literal>.</para>
    </sect1>

    <sect1 label="19.4" id="\AT">
      <title><literal>\@</literal></title>
      <para><indexterm role="fn"><primary>\@</primary></indexterm>
The <literal>\@</literal> command makes the following punctuation character end a
sentence even if it normally would not.  This is typically used after
a capital letter.  Here are side-by-side examples with and without
<literal>\@</literal>:</para>
      <screen>
&hellip; in C\@.  Pascal, though &hellip;
&hellip; in C.  Pascal, though &hellip;
</screen>
      <para role="continues">produces</para>
<!-- Texinfo does it differently, but the result is the same. -->
      <blockquote>
        <para>&hellip; in C.  Pascal, though &hellip;
&hellip; in C.  Pascal, though &hellip;</para>
      </blockquote>
    </sect1>

    <sect1 label="19.5" id="\thinspace">
      <title><literal>\thinspace</literal></title>
      <para><indexterm role="fn"><primary>\thinspace</primary></indexterm>
<literal>\thinspace</literal> produces an unbreakable and unstretchable space that
is 1/6 of an em.  This is the proper space to use in nested quotes, as
in '&rdquo;.</para>
    </sect1>

    <sect1 label="19.6" id="\/">
      <title><literal>\/</literal></title>
      <para><indexterm role="fn"><primary>\/</primary></indexterm>
The <literal>\/</literal> command produces an <firstterm>italic correction</firstterm>.  This is a
small space defined by the font designer for a given character,
to avoid the character colliding with whatever follows.  The italic
<wordasword>f</wordasword> character typically has a large italic correction value.</para>
      <para>If the following character is a period or comma, it's not necessary to
insert an italic correction, since those punctuation symbols have a
very small height.  However, with semicolons or colons, as well as
normal letters, it can help. Compare
<wordasword>f: f;</wordasword> (in the &tex; output, the `f's are nicely separated)
with <wordasword>f: f;</wordasword>.</para>
      <para>Despite the name, roman characters can also have an italic
correction.  Compare
pdf&tex; (in the &tex; output, there is a small space after the `f')
with pdf&tex;.</para>
    </sect1>

    <sect1 label="19.7" id="\hrulefill">
      <title><literal>\hrulefill</literal></title>
      <para><indexterm role="fn"><primary>\hrulefill</primary></indexterm>
The <literal>\hrulefill</literal> fill command produces a &ldquo;rubber length&rdquo; which can
stretch or shrink horizontally.  It will be filled with a horizontal
rule.</para>
    </sect1>

    <sect1 label="19.8" id="\dotfill">
      <title><literal>\dotfill</literal></title>
      <para><indexterm role="fn"><primary>\dotfill</primary></indexterm>
The <literal>\dotfill</literal> command produces a &ldquo;rubber length&rdquo; that fills
with dots instead of just white space.</para>
<!-- xx undone -->
    </sect1>

    <sect1 label="19.9" id="\addvspace">
      <title><literal>\addvspace</literal></title>
      <para><indexterm role="fn"><primary>\addvspace</primary></indexterm><indexterm role="cp"><primary>vertical space</primary></indexterm><indexterm role="cp"><primary>space, inserting vertical</primary></indexterm>
<literal>\addvspace{length}</literal></para>
      <para>The <literal>\addvspace</literal> command normally adds a vertical space of height
length.  However, if vertical space has already been added to the same
point in the output by a previous <literal>\addvspace</literal> command, then this
command will not add more space than needed to make the natural length
of the total vertical space equal to <literal>length</literal>.</para>
    </sect1>

    <sect1 label="19.10" id="\bigskip-\medskip-\smallskip">
      <title><literal>\bigskip \medskip \smallskip</literal></title>
      <para>These commands produce a given amount of space.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\bigskip</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\bigskip</primary></indexterm><indexterm role="fn"><primary>\bigskipamount</primary></indexterm>The same as <literal>\vspace{bigskipamount}</literal>, ordinarily about one line
space (with stretch and shrink).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\medskip</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\medskip</primary></indexterm><indexterm role="fn"><primary>\medskipamount</primary></indexterm>The same as <literal>\vspace{medskipamount}</literal>, ordinarily
about half of a line space (with stretch and shrink).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\smallskip</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\smallskip</primary></indexterm><indexterm role="fn"><primary>\smallskipamount</primary></indexterm>The same as <literal>\vspace{smallskipamount}</literal>, ordinarily about a
quarter of a line space (with stretch and shrink).</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>The <literal>\...amount</literal> parameters are determined by the document class.</para>
    </sect1>

    <sect1 label="19.11" id="\vfill">
      <title><literal>\vfill</literal></title>
      <para><indexterm role="fn"><primary>\vfill</primary></indexterm>
The <literal>\vfill</literal> fill command produces a rubber length (glue) which
can stretch or shrink vertically as far as needed.  It's equivalent to
<literal>\vspace{\fill}</literal> (see <xref linkend="\hfill"></xref>).</para>
    </sect1>

    <sect1 label="19.12" id="\vspace">
      <title><literal>\vspace[*]{<replaceable>length</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\vspace</primary></indexterm>
Synopsis:</para>
      <screen>
\vspace[*]{<replaceable>length</replaceable>}
</screen>
      <para>The <literal>\vspace</literal> command adds the vertical space <replaceable>length</replaceable>, i.e.,
a rubber length.  <replaceable>length</replaceable> can be negative or positive.</para>
      <para>Ordinarily, &latex; removes vertical space added by <literal>\vspace</literal> at
the top or bottom of a page.  With the optional <literal>*</literal> argument, the
space is not removed.</para>
    </sect1>
  </chapter>

  <chapter label="20" id="Boxes">
    <title>Boxes</title>
    <para><indexterm role="cp"><primary>boxes</primary></indexterm>
All the predefined length parameters (see <xref linkend="Predefined-lengths"></xref>) can be
used in the arguments of the box-making commands.</para>

    <sect1 label="20.1" id="\mbox">
      <title><literal>\mbox{<replaceable>text}</replaceable></literal></title>
      <para><indexterm role="fn"><primary>\mbox</primary></indexterm>
<indexterm role="cp"><primary>hyphenation, preventing</primary></indexterm>The <literal>\mbox</literal> command creates a box just wide enough to hold the
text created by its argument.  The <replaceable>text</replaceable> is not broken into
lines, so it can be used to prevent hyphenation.</para>
    </sect1>

    <sect1 label="20.2" id="\fbox-and-\framebox">
      <title><literal>\fbox</literal> and <literal>\framebox</literal></title>
      <para><indexterm role="fn"><primary>\fbox</primary></indexterm><indexterm role="fn"><primary>\framebox</primary></indexterm>
Synopses:</para>
      <screen>
\fbox{<replaceable>text</replaceable>}
\framebox[<replaceable>width</replaceable>][<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
</screen>
      <para>The <literal>\fbox</literal> and <literal>\framebox</literal> commands are like <literal>\mbox</literal>,
except that they put a frame around the outside of the box being created.</para>
      <para>In addition, the <literal>\framebox</literal> command allows for explicit
specification of the box width with the optional <replaceable>width</replaceable> argument
(a dimension), and positioning with the optional <replaceable>position</replaceable>
argument. 
<!-- xxref -->
<indexterm role="fn"><primary>\fboxrule</primary></indexterm><indexterm role="fn"><primary>\fboxsep</primary></indexterm>Both commands produce a rule of thickness <literal>\fboxrule</literal> (default
&lsquo;<literal>.4pt</literal>&rsquo;), and leave a space of <literal>\fboxsep</literal> (default
&lsquo;<literal>3pt</literal>&rsquo;) between the rule and the contents of the box.</para>
      <para>See <xref linkend="\framebox-(picture)"></xref>, for the <literal>\framebox</literal> command in the
<literal>picture</literal> environment.</para>
    </sect1>

    <sect1 label="20.3" id="lrbox">
      <title><literal>lrbox</literal></title>
      <para><indexterm role="fn"><primary>lrbox</primary></indexterm>
<literal>\begin{lrbox}{cmd} text \end{lrbox}</literal></para>
      <para>This is the environment form of <literal>\sbox</literal>.</para>
      <para>The text inside the environment is saved in the box <literal>cmd</literal>, which
must have been declared with <literal>\newsavebox</literal>.</para>
    </sect1>

    <sect1 label="20.4" id="\makebox">
      <title><literal>\makebox</literal></title>
      <para><indexterm role="fn"><primary>\makebox</primary></indexterm>
Synopsis:</para>
      <screen>
\makebox[<replaceable>width</replaceable>][<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
</screen>
      <para>The <literal>\makebox</literal> command creates a box just wide enough to contain
the <replaceable>text</replaceable> specified.  The width of the box is specified by the
optional <replaceable>width</replaceable> argument.  The position of the text within the box
is determined by the optional <replaceable>position</replaceable> argument, which may take
the following values:</para>
      <variablelist>
        <varlistentry>
          <term><literal>c</literal></term>
          <listitem>
            <para>Centered (default).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>l</literal></term>
          <listitem>
            <para>Flush left.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>r</literal></term>
          <listitem>
            <para>Flush right.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>s</literal></term>
          <listitem>
            <para>Stretch (justify) across entire <replaceable>width</replaceable>; <replaceable>text</replaceable> must contain
stretchable space for this to work.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para><literal>\makebox</literal> is also used within the picture environment
see <xref linkend="\makebox-(picture)"></xref>.</para>
    </sect1>

    <sect1 label="20.5" id="\parbox">
      <title><literal>\parbox</literal></title>
      <para><indexterm role="fn"><primary>\parbox</primary></indexterm>
Synopsis:</para>
      <screen>
\parbox[<replaceable>position</replaceable>][<replaceable>height</replaceable>][<replaceable>inner-pos</replaceable>]{<replaceable>width</replaceable>}{<replaceable>text</replaceable>}
</screen>
      <para>The <literal>\parbox</literal> command produces a box whose contents are created
in <literal>paragraph</literal> mode.  It should be used to make a box small
pieces of text, with nothing fancy inside.  In particular, you
shouldn't use any paragraph-making environments inside a
<literal>\parbox</literal> argument.  For larger pieces of text, including ones
containing a paragraph-making environment, you should use a
<literal>minipage</literal> environment (see <xref linkend="minipage"></xref>).</para>
      <para><literal>\parbox</literal> has two mandatory arguments:</para>
      <variablelist>
        <varlistentry>
          <term><replaceable>width</replaceable></term>
          <listitem>
            <para>the width of the parbox;</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>text</replaceable></term>
          <listitem>
            <para>the text that goes inside the parbox.</para>
          </listitem>
        </varlistentry>
      </variablelist>
      <para>The optional <replaceable>position</replaceable> argument allows you to align either the
top or bottom line in the parbox with the baseline of the surrounding
text (default is top).</para>
      <para>The optional <replaceable>height</replaceable> argument overrides the natural height of the box.</para>
      <para>The <replaceable>inner-pos</replaceable> argument controls the placement of the text inside
the box, as follows; if it is not specified, <replaceable>position</replaceable> is used.</para>
      <variablelist>
        <varlistentry>
          <term><literal>t</literal></term>
          <listitem>
            <para>text is placed at the top of the box.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>c</literal></term>
          <listitem>
            <para>text is centered in the box.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>b</literal></term>
          <listitem>
            <para>text is placed at the bottom of the box.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>s</literal></term>
          <listitem>
            <para>stretch vertically; the text must contain vertically stretchable space
for this to work.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="20.6" id="\raisebox">
      <title><literal>\raisebox</literal></title>
      <para><indexterm role="fn"><primary>\raisebox</primary></indexterm>
Synopsis:</para>
      <screen>
\raisebox{distance}[<replaceable>height</replaceable>][<replaceable>depth</replaceable>]{text}
</screen>
      <para>The <literal>\raisebox</literal> command raises or lowers <replaceable>text</replaceable>.  The first
mandatory argument specifies how high <replaceable>text</replaceable> is to be raised (or
lowered if it is a negative amount).  <replaceable>text</replaceable> itself is processed
in LR mode.</para>
      <para>The optional arguments <replaceable>height</replaceable> and <replaceable>depth</replaceable> are dimensions.
If they are specified, &latex; treats <replaceable>text</replaceable> as extending a
certain distance above the baseline (height) or below (depth),
ignoring its natural height and depth.</para>
    </sect1>

    <sect1 label="20.7" id="\savebox">
      <title><literal>\savebox</literal></title>
      <para><indexterm role="fn"><primary>\savebox</primary></indexterm>
Synopsis:</para>
      <screen>
\savebox{<replaceable>\boxcmd</replaceable>}[<replaceable>width</replaceable>][<replaceable>pos</replaceable>]{<replaceable>text</replaceable>}
</screen>
      <para>This command typeset <replaceable>text</replaceable> in a box just as with <literal>\makebox</literal>
(see <xref linkend="\makebox"></xref>), except that instead of printing the resulting box,
it saves it in the box labeled <replaceable>\boxcmd</replaceable>, which must have been
declared with <literal>\newsavebox</literal> (see <xref linkend="\newsavebox"></xref>).</para>
    </sect1>

    <sect1 label="20.8" id="\sbox">
      <title><literal>\sbox{<replaceable>\boxcmd</replaceable>}{<replaceable>text</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\sbox</primary></indexterm>
Synopsis:</para>
      <screen>
\sbox{<replaceable>\boxcmd</replaceable>}{<replaceable>text</replaceable>}
</screen>
      <para><literal>\sbox</literal> types <replaceable>text</replaceable> in a box just as with <literal>\mbox</literal>
(see <xref linkend="\mbox"></xref>) except that instead of the resulting box being
included in the normal output, it is saved in the box labeled
<replaceable>\boxcmd</replaceable>.  <replaceable>\boxcmd</replaceable> must have been previously declared with
<literal>\newsavebox</literal> (see <xref linkend="\newsavebox"></xref>).</para>
    </sect1>

    <sect1 label="20.9" id="\usebox">
      <title><literal>\usebox{<replaceable>\boxcmd</replaceable></literal></title>
      <para><indexterm role="fn"><primary>\usebox</primary></indexterm>
Synopsis:</para>
      <screen>
\usebox{<replaceable>\boxcmd</replaceable>}
</screen>
      <para><literal>\usebox</literal> producesthe box most recently saved in the bin
<replaceable>\boxcmd</replaceable> by a <literal>\savebox</literal> command (see <xref linkend="\savebox"></xref>).</para>
    </sect1>
  </chapter>

  <chapter label="21" id="Special-insertions">
    <title>Special insertions</title>
    <para>&latex; provides commands for inserting characters that have a
special meaning do not correspond to simple characters you can type.</para>

    <sect1 label="21.1" id="Reserved-characters">
      <title>Reserved characters</title>
      <para><indexterm role="cp"><primary>reserved characters</primary></indexterm><indexterm role="cp"><primary>characters, reserved</primary></indexterm>
The following characters play a special role in &latex; and are called
&ldquo;reserved characters&rdquo; or &ldquo;special characters&rdquo;.</para>
      <screen>
# $ % &amp; ~ _ ^ \ { }
</screen>
      <para><indexterm role="fn"><primary>\#</primary></indexterm><indexterm role="fn"><primary>\$</primary></indexterm><indexterm role="fn"><primary>\%</primary></indexterm><indexterm role="fn"><primary>\&amp;</primary></indexterm><indexterm role="fn"><primary>\_</primary></indexterm><indexterm role="fn"><primary>\{</primary></indexterm><indexterm role="fn"><primary>\}</primary></indexterm>Whenever you write one of these characters into your file, &latex;
will do something special.  If you simply want the character to be
printed as itself, include a <literal>\</literal> in front of the character.  For
example, <literal>\$</literal> will produce <literal>$</literal> in your output.</para>
      <para><indexterm role="fn"><primary>\backslash</primary></indexterm>One exception to this rule is <literal>\</literal> itself, because <literal>\\</literal> has
its own special (context-dependent) meaning.  A roman \ is produced by
typing <literal>$\backslash$</literal> in your file, and a typewriter <literal>\</literal> is
produced by using &lsquo;<literal>\</literal>&rsquo; in a verbatim command (see <xref linkend="verbatim"></xref>).</para>
      <para><indexterm role="fn"><primary>\~</primary></indexterm><indexterm role="fn"><primary>\^</primary></indexterm>Also, <literal>\~</literal> and <literal>\^</literal> place tilde and circumflex accents over
the following letter, as in &otilde; and &ocirc; (see <xref linkend="Accents"></xref>); to get
a standalone <literal>~</literal> or <literal>^</literal>, you can again use a verbatim
command.</para>
      <para><indexterm role="fn"><primary>\symbol</primary></indexterm><indexterm role="cp"><primary>accessing any character of a font</primary></indexterm>
Finally, you can access any character of the current font once you
know its number by using the <literal>\symbol</literal> command. For example, the
visible space character used in the <literal>\verb*</literal> command has the code
decimal 32, so it can be typed as <literal>\symbol{32}</literal>.</para>
      <para>You can also specify octal numbers with <literal>'</literal> or hexadecimal numbers
with <literal>"</literal>, so the previous example could also be written as
<literal>\symbol{'40}</literal> or <literal>\symbol{"20}</literal>.</para>
    </sect1>

    <sect1 label="21.2" id="Text-symbols">
      <title>Text symbols</title>
      <para><indexterm role="cp"><primary>text symbols</primary></indexterm>&latex; provides commands to generate a number of non-letter symbols
in running text.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\copyright</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>copyright symbol</primary></indexterm>The copyright symbol, &copy;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\dag</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>dagger, in text</primary></indexterm>The dagger symbol (in text).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ddag</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>double dagger, in text</primary></indexterm>The double dagger symbol (in text).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\LaTeX</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>&latex; logo</primary></indexterm><indexterm role="cp"><primary>logo, &latex;</primary></indexterm>The &latex; logo.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ldots</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>ellipsis</primary></indexterm>An ellipsis (three dots at the baseline): `&hellip;'.  This
command also works in math mode.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\lq</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>left quote</primary></indexterm><indexterm role="cp"><primary>opening quote</primary></indexterm>Left (opening) quote: `.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\P</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>paragraph sign</primary></indexterm><indexterm role="cp"><primary>pilcrow</primary></indexterm>Paragraph sign (pilcrow).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\pounds</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>pounds symbol</primary></indexterm><indexterm role="cp"><primary>sterling symbol</primary></indexterm>English pounds sterling.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\rq</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>right quote</primary></indexterm><indexterm role="cp"><primary>closing quote</primary></indexterm>Right (closing) quote: '.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\S</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>section symbol</primary></indexterm>Section symbol.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\TeX</literal></term>
          <listitem>
            <para><indexterm role="cp"><primary>&tex; logo</primary></indexterm><indexterm role="cp"><primary>logo, &tex;</primary></indexterm>The &tex; logo.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="21.3" id="Accents">
      <title>Accents</title>
      <para><indexterm role="cp"><primary>accents</primary></indexterm><indexterm role="cp"><primary>characters, accented</primary></indexterm><indexterm role="cp"><primary>letters, accented</primary></indexterm>
&latex; has wide support for many of the world's scripts and
languages, through the <literal>babel</literal> package and related support.  This
section does not attempt to cover all that support.  It merely the
core &latex; commands for creating accented characters.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\"</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\" (umlaut accent)</primary></indexterm><indexterm role="cp"><primary>umlaut accent</primary></indexterm>Produces an umlaut, as in &ouml;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\'</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\' (acute accent)</primary></indexterm><indexterm role="cp"><primary>acute accent</primary></indexterm>Produces an acute accent, as in &oacute;.  In the <literal>tabbing</literal>
environment, pushes current column to the right of the previous column
(see <xref linkend="tabbing"></xref>).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\.</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\. (dot-over accent)</primary></indexterm><indexterm role="cp"><primary>dot accent</primary></indexterm><indexterm role="cp"><primary>dot-over accent</primary></indexterm>Produces a dot accent over the following, as in o..</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\=</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\= (macron accent)</primary></indexterm><indexterm role="cp"><primary>macron accent</primary></indexterm><indexterm role="cp"><primary>overbar accent</primary></indexterm><indexterm role="cp"><primary>bar-over accent</primary></indexterm>Produces a macron (overbar) accent over the following, as in o&macr;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\^</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\^ (circumflex accent)</primary></indexterm><indexterm role="cp"><primary>circumflex accent</primary></indexterm><indexterm role="cp"><primary>hat accent</primary></indexterm>Produces a circumflex (hat) accent over the following, as in &ocirc;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\`</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\` (grave accent)</primary></indexterm><indexterm role="cp"><primary>grave accent</primary></indexterm>Produces a grave accent over the following, as in &ograve;.  In the
<literal>tabbing</literal> environment, move following text to the right margin
(see <xref linkend="tabbing"></xref>).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\~</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\~ (tilde accent)</primary></indexterm><indexterm role="cp"><primary>tilde accent</primary></indexterm>Produces a tilde accent over the following, as in &ntilde;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\b</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\b (bar-under accent)</primary></indexterm><indexterm role="cp"><primary>bar-under accent</primary></indexterm>Produces a bar accent under the following, as in o_.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\c</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\c (cedilla accent)</primary></indexterm><indexterm role="cp"><primary>cedilla accent</primary></indexterm>Produces a cedilla accent under the following, as in 
<!-- {c}. --></para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\d</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\d (dot-under accent)</primary></indexterm><indexterm role="cp"><primary>dot-under accent</primary></indexterm>Produces a dot accent under the following, as in .o.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\H</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\H (Hungarian umlaut accent)</primary></indexterm><indexterm role="cp"><primary>hungarian umlaut accent</primary></indexterm>Produces a long Hungarian umlaut accent over the following, as in o''.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\i</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\i (dotless i)</primary></indexterm><indexterm role="cp"><primary>dotless i</primary></indexterm>Produces a dotless i, as in `i'.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\j</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\j (dotless j)</primary></indexterm><indexterm role="cp"><primary>dotless j</primary></indexterm>Produces a dotless j, as in `j'.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\t</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\t (tie-after accent)</primary></indexterm><indexterm role="cp"><primary>tie-after accent</primary></indexterm>Produces a tie-after accent, as in `oo['.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\u</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\u (breve accent)</primary></indexterm><indexterm role="cp"><primary>breve accent</primary></indexterm>Produces a breve accent, as in `o('.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\v</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\v (breve accent)</primary></indexterm><indexterm role="cp"><primary>hacek accent</primary></indexterm><indexterm role="cp"><primary>check accent</primary></indexterm>Produces a h&aacute;c&lt;ek (check) accent, as in `o&lt;'.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="21.4" id="Non-English-characters">
      <title>Non-English characters</title>
      <para><indexterm role="cp"><primary>special characters</primary></indexterm><indexterm role="cp"><primary>non-English characters</primary></indexterm><indexterm role="cp"><primary>characters, non-English</primary></indexterm><indexterm role="cp"><primary>letters, non-English</primary></indexterm>
Here are the basic &latex; commands for inserting characters commonly
used in languages other than English.</para>
      <variablelist>
        <varlistentry>
          <term><literal>\aa</literal></term>
          <term><literal>\AA</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\aa (&aring;)</primary></indexterm><indexterm role="fn"><primary>\AA (&Aring;)</primary></indexterm><indexterm role="cp"><primary>aring</primary></indexterm>&aring; and &Aring;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ae</literal></term>
          <term><literal>\AE</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\ae (&aelig;)</primary></indexterm><indexterm role="fn"><primary>\AE (&AElig;)</primary></indexterm><indexterm role="cp"><primary>ae ligature</primary></indexterm>&aelig; and &AElig;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\l</literal></term>
          <term><literal>\L</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\l (/l)</primary></indexterm><indexterm role="fn"><primary>\L (/L)</primary></indexterm><indexterm role="cp"><primary>polish l</primary></indexterm>/l and /L.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\o</literal></term>
          <term><literal>\O</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\o (&oslash;)</primary></indexterm><indexterm role="fn"><primary>\O (&Oslash;)</primary></indexterm><indexterm role="cp"><primary>oslash</primary></indexterm>&oslash; and &Oslash;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\oe</literal></term>
          <term><literal>\OE</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\oe (&oelig;)</primary></indexterm><indexterm role="fn"><primary>\OE (&OElig;)</primary></indexterm><indexterm role="cp"><primary>oe ligature</primary></indexterm>&oelig; and &OElig;.</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><literal>\ss</literal></term>
          <listitem>
            <para><indexterm role="fn"><primary>\ss (&szlig;)</primary></indexterm><indexterm role="cp"><primary>es-zet German letter</primary></indexterm><indexterm role="cp"><primary>sharp S letters</primary></indexterm>&szlig;.</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="21.5" id="\rule">
      <title><literal>\rule</literal></title>
      <para><indexterm role="fn"><primary>\rule</primary></indexterm>
Synopsis:</para>
      <screen>
\rule[<replaceable>raise</replaceable>]{<replaceable>width</replaceable>}{<replaceable>thickness</replaceable>}
</screen>
      <para>The <literal>\rule</literal> command produces <firstterm>rules</firstterm>, that is, lines or
rectangles.  The arguments are:</para>
      <variablelist>
        <varlistentry>
          <term><replaceable>raise</replaceable></term>
          <listitem>
            <para>How high to raise the rule (optional).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>width</replaceable></term>
          <listitem>
            <para>The length of the rule (mandatory).</para>
          </listitem>
        </varlistentry>
        <varlistentry>
          <term><replaceable>thickness</replaceable></term>
          <listitem>
            <para>The thickness of the rule (mandatory).</para>
          </listitem>
        </varlistentry>
      </variablelist>
    </sect1>

    <sect1 label="21.6" id="\today">
      <title><literal>\today</literal></title>
      <para><indexterm role="fn"><primary>\today</primary></indexterm>
The <literal>\today</literal> command produces today's date, in the format
&lsquo;<literal><replaceable>month</replaceable> <replaceable>dd</replaceable>, <replaceable>yyyy</replaceable></literal>&rsquo;; for example, `July 4, 1976'.
It uses the predefined counters <literal>\day</literal>, <literal>\month</literal>, and
<literal>\year</literal> (see <xref linkend="\day-\month-\year"></xref>) to do this.  It is not
updated as the program runs.</para>
      <para><indexterm role="cp"><primary><literal>datetime</literal> package</primary></indexterm>The <literal>datetime</literal> package, among others, can produce a wide variety
of other date formats.</para>
    </sect1>
  </chapter>

  <chapter label="22" id="Splitting-the-input">
    <title>Splitting the input</title>
    <para><indexterm role="cp"><primary>splitting the input file</primary></indexterm><indexterm role="cp"><primary>input file</primary></indexterm>
A large document requires a lot of input.  Rather than putting the whole
input in a single large file, it's more efficient to split it into
several smaller ones.  Regardless of how many separate files you use,
there is one that is the root file; it is the one whose name you type
when you run &latex;.</para>

    <sect1 label="22.1" id="\include">
      <title><literal>\include</literal></title>
      <para><indexterm role="fn"><primary>\include</primary></indexterm>
Synopsis:</para>
      <screen>
\include{<replaceable>file</replaceable>}
</screen>
      <para>If no <literal>\includeonly</literal> command is present, the <literal>\include</literal>
command executes <literal>\clearpage</literal> to start a new page
(see <xref linkend="\clearpage"></xref>), then reads <replaceable>file</replaceable>, then does another
<literal>\clearpage</literal>.</para>
      <para>Given an <literal>\includeonly</literal> command, the <literal>\include</literal> actions are
only run if <replaceable>file</replaceable> is listed as an argument to
<literal>\includeonly</literal>.  See the next section.</para>
      <para><indexterm role="cp"><primary>nested <literal>\include</literal>, not allowed</primary></indexterm>The <literal>\include</literal> command may not appear in the preamble or in a file
read by another <literal>\include</literal> command.</para>
    </sect1>

    <sect1 label="22.2" id="\includeonly">
      <title>\<literal>includeonly</literal></title>
      <para><indexterm role="fn"><primary>\includeonly</primary></indexterm>
Synopsis:</para>
      <screen>
\includeonly{<replaceable>file1</replaceable>,<replaceable>file2</replaceable>,...}
</screen>
      <para>The <literal>\includeonly</literal> command controls which files will be read by
subsequent <literal>\include</literal> commands.  The list of filenames is
comma-separated. Each <replaceable>file</replaceable> must exactly match a filename
specified in a <literal>\include</literal> command for the selection to be
effective.</para>
      <para>This command can only appear in the preamble.</para>
    </sect1>

    <sect1 label="22.3" id="\input">
      <title>\input</title>
      <para><indexterm role="fn"><primary>\input</primary></indexterm>
Synopsis:</para>
      <screen>
\input{<replaceable>file</replaceable>}
</screen>
      <para>The <literal>\input</literal> command causes the specified <replaceable>file</replaceable> to be read
and processed, as if its contents had been inserted in the current
file at that point.</para>
      <para>If <replaceable>file</replaceable> does not end in &lsquo;<literal>.tex</literal>&rsquo; (e.g., &lsquo;<literal>foo</literal>&rsquo; or
&lsquo;<literal>foo.bar</literal>&rsquo;), it is first tried with that extension (&lsquo;<literal>foo.tex</literal>&rsquo;
or &lsquo;<literal>foo.bar.tex</literal>&rsquo;).  If that is not found, the original <replaceable>file</replaceable>
is tried (&lsquo;<literal>foo</literal>&rsquo; or &lsquo;<literal>foo.bar</literal>&rsquo;).</para>
    </sect1>
  </chapter>

  <chapter label="23" id="Front/back-matter">
    <title>Front/back matter</title>
    <sect1 label="23.1" id="Tables-of-contents">
      <title>Tables of contents</title>
      <para><indexterm role="cp"><primary>table of contents, creating</primary></indexterm>
<indexterm role="fn"><primary>\tableofcontents</primary></indexterm>A table of contents is produced with the <literal>\tableofcontents</literal>
command.  You put the command right where you want the table of
contents to go; &latex; does the rest for you.  A previous run must
have generated a <filename>.toc</filename> file.</para>
      <para>The <literal>\tableofcontents</literal> command produces a heading, but it does
not automatically start a new page.  If you want a new page after the
table of contents, write a <literal>\newpage</literal> command after the
<literal>\tableofcontents</literal> command.</para>
      <para><indexterm role="fn"><primary>\listoffigures</primary></indexterm><indexterm role="fn"><primary>\listoftables</primary></indexterm>The analogous commands <literal>\listoffigures</literal> and <literal>\listoftables</literal>
produce a list of figures and a list of tables, respectively.
Everything works exactly the same as for the table of contents.</para>
      <para><indexterm role="fn"><primary>\nofiles</primary></indexterm>The command <literal>\nofiles</literal> overrides these commands, and
<emphasis>prevents</emphasis> any of these lists from being generated.</para>

      <sect2 label="23.1.1" id="\addcontentsline">
        <title>\addcontentsline</title>
        <para><indexterm role="fn"><primary>\addcontentsline{<replaceable>ext</replaceable>}{<replaceable>unit</replaceable>}{<replaceable>text</replaceable>}</primary></indexterm><indexterm role="cp"><primary>table of contents entry, manually adding</primary></indexterm>
The <literal>\addcontentsline</literal>{<replaceable>ext</replaceable>}{<replaceable>unit</replaceable>}{<replaceable>text</replaceable>}
command adds an entry to the specified list or table where:</para>
        <variablelist>
          <varlistentry>
            <term><replaceable>ext</replaceable></term>
            <listitem>
              <para>The extension of the file on which information is to be written,
typically one of: <literal>toc</literal> (table of contents), <literal>lof</literal> (list of
figures), or <literal>lot</literal> (list of tables).</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><replaceable>unit</replaceable></term>
            <listitem>
              <para>The name of the sectional unit being added, typically one of the
following, matching the value of the <replaceable>ext</replaceable> argument:</para>
              <variablelist>
                <varlistentry>
                  <term><literal>toc</literal></term>
                  <listitem>
                    <para>The name of the sectional unit: <literal>part</literal>, <literal>chapter</literal>,
<literal>section</literal>, <literal>subsection</literal>, <literal>subsubsection</literal>.</para>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term><literal>lof</literal></term>
                  <listitem>
                    <para>For the list of figures.</para>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term><literal>lot</literal></term>
                  <listitem>
                    <para>For the list of tables.</para>
                  </listitem>
                </varlistentry>
              </variablelist>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><replaceable>entry</replaceable></term>
            <listitem>
              <para>The actual text of the entry.</para>
            </listitem>
          </varlistentry>
        </variablelist>
        <para><indexterm role="fn"><primary>\contentsline</primary></indexterm>What is written to the <filename>.<replaceable>ext</replaceable></filename> file is the
command <literal>\contentsline{<replaceable>unit</replaceable>}{<replaceable>name</replaceable>}</literal>.</para>
<!-- ?? how hardwired are these values?  other unit names? -->
      </sect2>

      <sect2 label="23.1.2" id="\addtocontents">
        <title>\addtocontents</title>
        <para><indexterm role="fn"><primary>\addtocontents{<replaceable>ext</replaceable>}{<replaceable>text</replaceable>}</primary></indexterm>
The <literal>\addtocontents</literal>{<replaceable>ext</replaceable>}{<replaceable>text</replaceable>} command adds text
(or formatting commands) directly to the <filename>.<replaceable>ext</replaceable></filename> file that
generates the table of contents or lists of figures or tables.</para>
        <variablelist>
          <varlistentry>
            <term><replaceable>ext</replaceable></term>
            <listitem>
              <para>The extension of the file on which information is to be written:
<filename>toc</filename> (table of contents), <filename>lof</filename> (list of figures), or
<filename>lot</filename> (list of tables).</para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><replaceable>text</replaceable></term>
            <listitem>
              <para>The text to be written.</para>
            </listitem>
          </varlistentry>
        </variablelist>
      </sect2>
    </sect1>

    <sect1 label="23.2" id="Glossaries">
      <title>Glossaries</title>
      <para><indexterm role="cp"><primary>glossaries</primary></indexterm>
<indexterm role="fn"><primary>\makeglossary</primary></indexterm>The command <literal>\makeglossary</literal> enables creating glossaries.</para>
      <para><indexterm role="fn"><primary>\glossary</primary></indexterm><indexterm role="cp"><primary><filename>.glo</filename> file</primary></indexterm>The command <literal>\glossary{<replaceable>text</replaceable>}</literal> writes a glossary entry for
<replaceable>text</replaceable> to an auxiliary file with the <filename>.glo</filename> extension.</para>
      <para><indexterm role="fn"><primary>\glossaryentry</primary></indexterm>Specifically, what gets written is the command
<literal>\glossaryentry{<replaceable>text</replaceable>}{<replaceable>pageno</replaceable>}</literal>, where
<replaceable>pageno</replaceable> is the current <literal>\thepage</literal> value.</para>
      <para>The <literal>glossary</literal> package on CTAN provides support for fancier
glossaries.</para>
    </sect1>

    <sect1 label="23.3" id="Indexes">
      <title>Indexes</title>
      <para><indexterm role="cp"><primary>indexes</primary></indexterm>
<indexterm role="fn"><primary>\makeindex</primary></indexterm>The command <literal>\makeindex</literal> enables creating indexes.  Put this in
the preamble.</para>
      <para><indexterm role="fn"><primary>\index</primary></indexterm><indexterm role="cp"><primary><filename>.idx</filename> file</primary></indexterm>The command <literal>\index{<replaceable>text</replaceable>}</literal> writes an index entry for
<replaceable>text</replaceable> to an auxiliary file with the <filename>.idx</filename> extension.</para>
      <para><indexterm role="fn"><primary>\indexentry</primary></indexterm>Specifically, what gets written is the command
<literal>\indexentry{<replaceable>text</replaceable>}{<replaceable>pageno</replaceable>}</literal>, where <replaceable>pageno</replaceable>
is the current <literal>\thepage</literal> value.</para>
      <para><indexterm role="cp"><primary>`see' and `see also' index entries</primary></indexterm>To generate a index entry for `bar' that says `See foo', use a
vertical bar: <literal>\index{bar|see{foo}}</literal>.  Use <literal>seealso</literal>
instead of <literal>see</literal> to make a `See also' entry.</para>
      <para><indexterm role="fn"><primary>\seename</primary></indexterm><indexterm role="fn"><primary>\alsoname</primary></indexterm>The text `See' is defined by the macro <literal>\seename</literal>, and `See also'
by the macro <literal>\alsoname</literal>.  These can be redefined for other
languages.</para>
      <para><indexterm role="cp"><primary><command>makeindex</command> program</primary></indexterm><indexterm role="cp"><primary><command>xindy</command> program</primary></indexterm><indexterm role="cp"><primary><filename>.ind</filename> file</primary></indexterm>The generated <filename>.idx</filename> file is then sorted with an external
command, usually either <command>makeindex</command>
(<ulink url="http://mirror.ctan.org/indexing/makeindex">http://mirror.ctan.org/indexing/makeindex</ulink>) or (the
multi-lingual) <command>xindy</command> (<ulink url="http://xindy.sourceforge.net">http://xindy.sourceforge.net</ulink>).
This results in a <filename>.ind</filename> file, which can then be read to typeset
the index.</para>
      <para><indexterm role="fn"><primary>printindex</primary></indexterm><indexterm role="cp"><primary><literal>makeidx</literal> package</primary></indexterm>The index is usually generated with the <literal>\printindex</literal> command.
This is defined in the <literal>makeidx</literal> package, so
<literal>\usepackage{makeidx}</literal> needs to be in the preamble.</para>
      <para><indexterm role="fn"><primary>indexspace</primary></indexterm>The rubber length <literal>\indexspace</literal> is inserted before each new
letter in the printed index; its default value is &lsquo;<literal>10pt plus5pt
minus3pt</literal>&rsquo;.</para>
      <para><indexterm role="cp"><primary><literal>showidx</literal> package</primary></indexterm>The <literal>showidx</literal> package causes each index entries to be shown in
the margin on the page where the entry appears.  This can help in
preparing the index.</para>
      <para><indexterm role="cp"><primary><literal>multind</literal> package</primary></indexterm>The <literal>multind</literal> package supports multiple indexes.  See also the
&tex; FAQ entry on this topic,
<ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind</ulink>.</para>
    </sect1>
  </chapter>

  <chapter label="24" id="Letters">
    <title>Letters</title>
    <para><indexterm role="cp"><primary>letters</primary></indexterm><indexterm role="cp"><primary>creating letters</primary></indexterm>
You can use &latex; to typeset letters, both personal and business.  The
<literal>letter</literal> document class is designed to make a number of letters at
once, although you can make just one if you so desire.</para>
    <para>Your <filename>.tex</filename> source file has the same minimum commands as the other
document classes, i.e., you must have the following commands as a
minimum:</para>
    <screen>
 \documentclass{letter}
 \begin{document}
  ... letters ...
 \end{document}
</screen>
    <para>Each letter is a <literal>letter</literal> environment, whose argument is the name
and address of the recipient.  For example, you might have:</para>
    <screen>
 \begin{letter}{Mr. Joe Smith\\ 2345 Princess St.
      \\ Edinburgh, EH1 1AA}
   ...
 \end{letter}
</screen>
    <para>The letter itself begins with the <literal>\opening</literal> command.  The text of
the letter follows.  It is typed as ordinary &latex; input.  Commands that
make no sense in a letter, like <literal>\chapter</literal>, do not work.  The letter
closes with a <literal>\closing</literal> command.</para>
    <para><indexterm role="fn"><primary>\\ for letters</primary></indexterm>After the <literal>closing</literal>, you can have additional material.  The
<literal>\cc</literal> command produces the usual &ldquo;cc: &hellip;&rdquo;.  There's also a
similar <literal>\encl</literal> command for a list of enclosures. With both these
commands, use <literal>\\</literal> to separate the items.</para>
    <para>These commands are used with the <literal>letter</literal> class.</para>

    <sect1 label="24.1" id="\address">
      <title>\address{<replaceable>return-address}</replaceable></title>
      <para><indexterm role="fn"><primary>\address</primary></indexterm>
The <literal>\address</literal> specifies the return address of a letter, as it
should appear on the letter and the envelope.  Separate lines of the
address should be separated by <literal>\\</literal> commands.</para>
      <para>If you do not make an <literal>\address</literal> declaration, then the letter
will be formatted for copying onto your organisation's standard
letterhead.  (See <xref linkend="Overview"></xref>, for details on your local
implementation).  If you give an <literal>\address</literal> declaration, then the
letter will be formatted as a personal letter.</para>
    </sect1>

    <sect1 label="24.2" id="\cc">
      <title><literal>\cc</literal></title>
      <para><indexterm role="fn"><primary>\cc</primary></indexterm><indexterm role="cp"><primary>cc list, in letters</primary></indexterm>
Synopsis:</para>
      <screen>
\cc{<replaceable>name1</replaceable>\\<replaceable>name2</replaceable>}
</screen>
      <para>Produce a list of <replaceable>name</replaceable>s the letter was copied to.  Each name is
printed on a separate line.</para>
    </sect1>

    <sect1 label="24.3" id="\closing">
      <title><literal>\closing</literal></title>
      <para><indexterm role="fn"><primary>\closing</primary></indexterm><indexterm role="cp"><primary>letters, ending</primary></indexterm><indexterm role="cp"><primary>closing letters</primary></indexterm>
Synopsis:</para>
      <screen>
\closing{text}
</screen>
      <para>A letter closes with a <literal>\closing</literal> command, for example,</para>
      <screen>
\closing{Best Regards,}
</screen>
    </sect1>

    <sect1 label="24.4" id="\encl">
      <title><literal>\encl</literal></title>
      <para><indexterm role="fn"><primary>\encl</primary></indexterm><indexterm role="cp"><primary>enclosure list</primary></indexterm>
Synopsis:</para>
      <screen>
\encl{<replaceable>line1</replaceable>\\<replaceable>line2</replaceable>}
</screen>
      <para>Declare a list of one more enclosures.</para>
    </sect1>

    <sect1 label="24.5" id="\location">
      <title><literal>\location</literal></title>
      <para><indexterm role="fn"><primary>\location</primary></indexterm>
<literal>\location{address}</literal></para>
      <para>This modifies your organisation's standard address.  This only appears
if the <literal>firstpage</literal> pagestyle is selected.</para>
    </sect1>

    <sect1 label="24.6" id="\makelabels">
      <title><literal>\makelabels</literal></title>
      <para><indexterm role="fn"><primary>\makelabels</primary></indexterm>
<literal>\makelabels{number}</literal></para>
      <para>If you issue this command in the preamble, &latex; will create a sheet of
address labels. This sheet will be output before the letters.</para>
    </sect1>

    <sect1 label="24.7" id="\name">
      <title><literal>\name</literal></title>
      <para><indexterm role="fn"><primary>\name</primary></indexterm>
<literal>\name{June Davenport}</literal></para>
      <para>Your name, used for printing on the envelope together with the return
address.</para>
    </sect1>

    <sect1 label="24.8" id="\opening">
      <title><literal>\opening{<replaceable>text</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\opening</primary></indexterm><indexterm role="cp"><primary>letters, starting</primary></indexterm>
Synopsis:</para>
      <screen>
\opening{<replaceable>text</replaceable>}
</screen>
      <para>A letter begins with the <literal>\opening</literal> command.  The mandatory
argument, <replaceable>text</replaceable>, is whatever text you wish to start your letter.
For instance:</para>
      <screen>
\opening{Dear Joe,}
</screen>
    </sect1>

    <sect1 label="24.9" id="\ps">
      <title><literal>\ps</literal></title>
      <para><indexterm role="fn"><primary>\ps</primary></indexterm><indexterm role="cp"><primary>postscript, in letters</primary></indexterm>
Use the <literal>\ps</literal> command to start a postscript in a letter, after
<literal>\closing</literal>.</para>
    </sect1>

    <sect1 label="24.10" id="\signature">
      <title><literal>\signature{<replaceable>text</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\signature</primary></indexterm>
Your name, as it should appear at the end of the letter underneath the
space for your signature.  <literal>\\</literal> starts a new line within
<replaceable>text</replaceable> as usual.</para>
    </sect1>

    <sect1 label="24.11" id="\startbreaks">
      <title><literal>\startbreaks</literal></title>
      <para><indexterm role="fn"><primary>\startbreaks</primary></indexterm>
<literal>\startbreaks</literal></para>
      <para>Used after a <literal>\stopbreaks</literal> command to allow page breaks again.</para>
    </sect1>

    <sect1 label="24.12" id="\stopbreaks">
      <title><literal>\stopbreaks</literal></title>
      <para><indexterm role="fn"><primary>\stopbreaks</primary></indexterm>
<literal>\stopbreaks</literal></para>
      <para>Inhibit page breaks until a <literal>\startbreaks</literal> command occurs.</para>
    </sect1>

    <sect1 label="24.13" id="\telephone">
      <title><literal>\telephone</literal></title>
      <para><indexterm role="fn"><primary>\telephone</primary></indexterm>
<literal>\telephone{number}</literal></para>
      <para>This is your telephone number.  This only appears if the
<literal>firstpage</literal> pagestyle is selected.</para>
    </sect1>
  </chapter>

  <chapter label="25" id="Terminal-Input/Output">
    <title>Terminal Input/Output</title>
    <para><indexterm role="cp"><primary>input/Output</primary></indexterm><indexterm role="cp"><primary>terminal Input/Output</primary></indexterm></para>

    <sect1 label="25.1" id="\typein">
      <title><literal>\typein[<replaceable>cmd</replaceable>]{<replaceable>msg</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\typein</primary></indexterm>
Synopsis:</para>
      <screen>
\typein[<replaceable>\cmd</replaceable>]{<replaceable>msg</replaceable>}
</screen>
      <para><literal>\typein</literal> prints <replaceable>msg</replaceable> on the terminal and causes &latex; to
stop and wait for you to type a line of input, ending with return.  If
the optional <replaceable>\cmd</replaceable> argument is omitted, the typed input is
processed as if it had been included in the input file in place of the
<literal>\typein</literal> command.  If the <replaceable>\cmd</replaceable> argument is present, it
must be a command name.  This command name is then defined or
redefined to be the typed input.</para>
    </sect1>

    <sect1 label="25.2" id="\typeout">
      <title><literal>\typeout{<replaceable>msg</replaceable>}</literal></title>
      <para><indexterm role="fn"><primary>\typeout</primary></indexterm>
Synopsis:</para>
      <screen>
\typeout{<replaceable>msg</replaceable>}
</screen>
      <para>Prints <literal>msg</literal> on the terminal and in the <literal>log</literal> file.
Commands in <literal>msg</literal> that are defined with <literal>\newcommand</literal> or
<literal>\renewcommand</literal> (among others) are replaced by their definitions
before being printed.</para>
      <para>&latex;'s usual rules for treating multiple spaces as a single space
and ignoring spaces after a command name apply to <literal>msg</literal>.  A
<literal>\space</literal> command in <literal>msg</literal> causes a single space to be
printed, independent of surrounding spaces.  A <literal>^^J</literal> in
<literal>msg</literal> prints a newline.</para>
    </sect1>
  </chapter>

  <chapter label="26" id="Command-Line">
    <title>Command Line</title>
    <para><indexterm role="cp"><primary>command Line</primary></indexterm>
The input file specification indicates the file to be formatted;
&tex; uses <filename>.tex</filename> as a default file extension.  If you omit the
input file entirely, &tex; accepts input from the terminal.  You
specify command options by supplying a string as a parameter to the
command; e.g.</para>
    <screen>
latex '\nonstopmode\input foo.tex'
</screen>
    <para role="continues">will process <filename>foo.tex</filename> without pausing after every error.</para>
    <para><indexterm role="cp"><primary>&lsquo;<literal>*</literal>&rsquo; prompt</primary></indexterm><indexterm role="cp"><primary>prompt, &lsquo;<literal>*</literal>&rsquo;</primary></indexterm><indexterm role="fn"><primary>\stop</primary></indexterm>If &latex; stops in the middle of the document and gives you a
&lsquo;<literal>*</literal>&rsquo; prompt, it is waiting for input.  You can type <literal>\stop</literal>
(and return) and it will prematurely end the document.</para>
  </chapter>

  <appendix id="Document-templates">
    <title>Document templates</title>
    <para><indexterm role="cp"><primary>document templates</primary></indexterm>
Although not reference material, perhaps these document templates will
be useful.</para>

    <sect1 id="book-template">
      <title><literal>book</literal> template</title>
      <screen>\documentclass{book}
\title{Book Class Template}
\author{Alex Author}

\begin{document}
\maketitle

\chapter{First}
Some text.

\chapter{Second}
Some other text.

\section{A subtopic}
The end.
\end{document}
</screen>
    </sect1>

    <sect1 id="beamer-template">
      <title><literal>beamer</literal> template</title>
      <para>The <literal>beamer</literal> class creates slides presentations.</para>
      <screen>\documentclass{beamer}

\title{Beamer Class template}
\author{Alex Author}
\date{July 31, 2007}

\begin{document}

\maketitle

% without [fragile], any {verbatim} code gets mysterious errors.
\begin{frame}[fragile]
 \frametitle{First Slide}

\begin{verbatim}
  This is \verbatim!
\end{verbatim}

\end{frame}

\end{document}

</screen>
    </sect1>

    <sect1 id="tugboat-template">
      <title><literal>tugboat</literal> template</title>
      <para><citetitle>TUGboat</citetitle> is the journal of the &tex; Users Group,
<ulink url="http://tug.org/TUGboat">http://tug.org/TUGboat</ulink>.</para>
      <screen>\documentclass{ltugboat}  % ltugproc for proceedings

\usepackage{graphicx}
\usepackage{ifpdf}
\ifpdf
  \usepackage[breaklinks,colorlinks,linkcolor=black,citecolor=black,
              urlcolor=black]{hyperref}
\else
  \usepackage{url}
\fi

\begin{document}

\title{Example \TUB\ Regular Article}

% repeat info for each author.
\author{First Last}
\address{Street Address \\ Town, Postal \\ Country}
\netaddress{user (at) example dot org}
\personalURL{http://example.org/~user/}

\maketitle

% The abstract comes after \maketitle in ltugboat.
\begin{abstract}
This is an example article for a regular \TUB{} issue.
\end{abstract}

\section{Introduction}

This is an example article for \TUB, from
\url{http://tug.org/TUGboat/location.html}.

We recommend the graphicx package for image inclusions, and the hyperref
package for active url's (in the \acro{PDF} output).  \TUB\ is produced
using \acro{PDF} files exclusively, nowadays.

The \texttt{ltug*} classes provide these abbreviations, among many others:

{\small
\begin{verbatim}
\AllTeX \AMS \AmS \AmSLaTeX \AmSTeX \aw \AW
\BibTeX \CandT \CTAN \DTD \DVItoVDU \HTML
\ISBN \ISSN \JTeX \JoT \LAMSTeX \LaTeXe
\Mc \mf \MFB \mtex \pcMF \PCTeX \pcTeX \Pas
\PiC \PiCTeX \plain \POBox \PS
\SC \SGML \SliTeX \TANGLE \TB \TP \TUB \TUG
\tug \UG \UNIX \VAX \VorTeX \XeT \WEB \WEAVE

\Dash \dash \vellipsis \bull \cents \Dag
\careof \thinskip

\acro{FRED} -&gt; {\sc fred}  % please use!
\cs{fred}   -&gt; \fred
\env{fred}  -&gt; \begin{fred}
\meta{fred} -&gt; &lt;fred&gt;
\nth{n}     -&gt; 1st, 2nd, ...
\sfrac{3/4} -&gt; 3/4
\booktitle{Book of Fred}
\end{verbatim}
}

For more information, see the ltubguid document at:
\url{http://mirror.ctan.org/macros/latex/contrib/tugboat}

Email \verb|tugboat@tug.org| if problems or questions.


\bibliographystyle{plain}  % we recommend the plain bibliography style
\nocite{book-minimal}      % just making the bibliography non-empty
\bibliography{xampl}       % xampl.bib comes with BibTeX


\makesignature  % not in ltugproc
\end{document}
</screen>
    </sect1>
  </appendix>

  <chapter label="" xreflabel="Concept Index" id="Concept-Index">
    <title>Concept Index</title>
    <index></index>
<!-- The name of the `Command Index' node must NOT be altered for ltx-help.el. -->
  </chapter>

  <chapter label="" xreflabel="Command Index" id="Command-Index">
    <title>Command Index</title>
    <index></index>
  </chapter>
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