The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" name="pipeline" version="3.0">
<p:output port="result"/>
<p:identity>
<p:with-input>
<doc1/>
<doc2/>
</p:with-input>
</p:identity>
<p:if test="false()">
<p:output port="result" primary="true" sequence="false"/>
<p:output port="secondary" sequence="false" pipe="@secondary"/>
<p:identity name="secondary">
<p:with-input>
<secondary/>
</p:with-input>
</p:identity>
<p:insert match="/" position="last-child">
<p:with-input>
<doc/>
</p:with-input>
<p:with-input port="insertion">
<element/>
</p:with-input>
</p:insert>
</p:if>
<p:count>
<p:with-input pipe="secondary"/>
</p:count>
</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:ns prefix="c" uri="http://www.w3.org/ns/xproc-step"/>
<s:pattern>
<s:rule context="/">
<s:assert test="c:result">The root element is not 'c:result'.</s:assert>
<s:assert test="c:result/text()='0'">Text child of 'c:result' is not '0'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
