<?xml version="1.0"?> <!DOCTYPE example PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"> <example><title>The Grand Unified Theory</title><para><comment>Some details are still a bit shaky</comment> … Q.E.D. </para></example>