\def\emtabbing{\lineskip \z@\let\>\@emrtab\let\<\@ltab\let\=\@emsettab
     \let\+\@tabplus\let\-\@tabminus\let\`\@tabrj\let\'\@tablab
     \let\\=\@tabcr
     \global\@hightab\@firsttab
     \global\@nxttabmar\@firsttab
     \dimen\@firsttab\@totalleftmargin
     \global\@tabpush0 \global\@rjfieldfalse
     \trivlist \item[]\if@minipage\else\vskip\parskip\fi
     \setbox\@tabfbox\hbox{\rlap{\indent\hskip\@totalleftmargin
       \the\everypar}}\def\@itemfudge{\box\@tabfbox}\@startline\ignorespaces}

\def\endemtabbing{\@stopline\ifnum\@tabpush > 0 \@badpoptabs \fi\endtrivlist}
\def\@emsettab{\@settab\em}
\def\@emrtab{\@rtab\em}