<!DOCTYPE equation PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
          "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<equation id="mathphrase.example.1">
<title>Fermat's Last Theorem</title>
  <alt>x^n + y^n ≠ z^n ∀ n > 2</alt>
  <mathphrase>x<superscript>n</superscript>
+ y<superscript>n</superscript>
≠ z<superscript>n</superscript>
∀ n ≠ 2</mathphrase>
</equation>