The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" name="pipeline" version="3.0">
<p:output port="result"/>
<p:xinclude>
<p:with-input>
<document>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../documents/include-doc-001.xml" xpointer="contained-section"/>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="../documents/include-doc-001.xml" xpointer="xincluded-section"/>
</document>
</p:with-input>
</p:xinclude>
</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="document">Root element is not 'document'.</s:assert>
<s:assert test="document/p[1]/@xml:id='contained-section'">First 'p' does not have id 'contained-section'.</s:assert>
<s:assert test="document/p[2]/@xml:id='xincluded-section'">Second 'p' does not have id 'xincluded-section'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
