The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:xquery>
<p:with-input port="source">
<p:inline content-type="text/html">
<document>
<title>Some Title</title>
<para>Some paragraph.</para>
</document>
</p:inline>
</p:with-input>
<p:with-input port="query">
<result>{{//title}}</result>
</p:with-input>
</p:xquery>
</p:declare-step>
Schematron validation
<s:schema xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:pattern>
<s:rule context="/">
<s:assert test="result">Root element is not 'result'.</s:assert>
<s:assert test="result/title">Root element does not have child 'title'.</s:assert>
<s:assert test="result/title/text()='Some Title'">The text of element 'title' is not 'Some Title'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
