The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" xmlns:x="http://dummy" version="3.0">
<p:output port="result"/>
<p:option name="top-level" select="'top'"/>
<p:declare-step type="x:inner">
<p:output port="result"/>
<p:option name="inner" select="'fail'"/>
<p:identity>
<p:with-input>
<inner>{$inner}</inner>
</p:with-input>
</p:identity>
</p:declare-step>
<p:identity name="two">
<p:with-input>
<top>{$top-level}</top>
</p:with-input>
</p:identity>
<x:inner name="one" inner="pass"/>
<p:wrap-sequence wrapper="wrapper">
<p:with-input>
<p:pipe step="one"/>
<p:pipe step="two"/>
</p:with-input>
</p:wrap-sequence>
</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="p" uri="http://www.w3.org/ns/xproc"/>
<s:pattern>
<s:rule context="/*">
<s:assert test="self::wrapper">The pipeline root is not wrapper.</s:assert>
</s:rule>
<s:rule context="/wrapper">
<s:assert test="inner[.='pass']">Inner has the wrong value.</s:assert>
<s:assert test="top[.='top']">Top has the wrong value.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
