The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" xmlns:test="http://test" version="3.0">
<p:output port="result">
<p:declare-step type="test:step-1">
<p:output port="result">
<p:declare-step type="test:step-2">
<p:output port="result">
<p:identity>
<p:with-input>
<doc/>
</p:with-input>
</p:identity>
</p:declare-step>
<test:step-2/>
</p:declare-step>
<p:declare-step type="test:step-2">
<p:output port="result">
<p:identity>
<p:with-input>
<doc1/>
</p:with-input>
</p:identity>
</p:declare-step>
<test:step-1 name="one">
<test:step-2 name="two">
<p:wrap-sequence wrapper="result">
<p:with-input pipe="@one @two">
</p:wrap-sequence>
</p:declare-step>
Schematron validation
<s:schema xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:pattern>
<s:rule context="/">
<s:assert test="result">The document root is not 'result'.</s:assert>
<s:assert test="count(result/*) = 2">Result does not have two children.</s:assert>
<s:assert test="result/*[1]/name()='doc'">First child of result is 'doc'.</s:assert>
<s:assert test="result/*[2]/name()='doc1'">First child of result is 'doc1'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
