The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" name="main" version="3.0">
<p:output port="result"/>
<p:identity name="one">
<p:with-input port="source">
<p:inline>
<doc>There are <t>elements</t> in here. A couple of <t>elements</t>.</doc>
</p:inline>
</p:with-input>
</p:identity>
<p:variable name="bar" select="count(//*)"/>
<p:identity name="two">
<p:with-input port="source">
<p:inline>
<doc count="{$bar}">Counts the number of nodes.
The number of the nodes is <number>{$bar}</number>.
<toggle class="{$bar}" p:inline-expand-text="false">{$bar}</toggle>
</doc>
</p:inline>
</p:with-input>
</p:identity>
</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::doc">The pipeline root is not doc.</s:assert>
</s:rule>
<s:rule context="number">
<s:assert test=". = 3">The number of nodes in the TVT is incorrect.</s:assert>
</s:rule>
<s:rule context="toggle">
<s:assert test="@class = 3">The number of nodes in the toggle AVT is incorrect.</s:assert>
</s:rule>
<s:rule context="toggle">
<s:assert test=". = '{{$bar}}'">The toggled content is incorrect.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
