&lt;!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"&gt;
&lt;para&gt;
Einstein's theory of relativity includes one of the most
widely recognized formulas in the world:
&lt;inlineequation&gt;
  &lt;alt&gt;e=mc^2&lt;/alt&gt;
  &lt;graphic fileref="figures/emc2.png"/&gt;
&lt;/inlineequation&gt;
&lt;/para&gt;