The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:pack wrapper="wrap">
<p:with-input port="source">
<p:inline>
<!-- comment1 -->
<doc1/>
<?pi1 target?>
</p:inline>
</p:with-input>
<p:with-input port="alternate">
<p:inline>
<?pi2?>
<doc2/>
<!-- comment2 -->
</p:inline>
</p:with-input>
</p:pack>
<p:wrap-sequence wrapper="doc"/>
</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="doc">The document root is not doc.</s:assert>
<s:assert test="doc/wrap/child::node()[1] instance of text()">First child of wrap should be a text.</s:assert>
<s:assert test="doc/wrap/child::node()[2] instance of comment()">Second child of wrap should be a comment.</s:assert>
<s:assert test="doc/wrap/child::node()[3] instance of text()">Third child of wrap should be a text.</s:assert>
<s:assert test="doc/wrap/child::node()[4] instance of element()">Forth child of wrap should be an element.</s:assert>
<s:assert test="doc/wrap/child::node()[5] instance of text()">Fifth child of wrap should be a text.</s:assert>
<s:assert test="doc/wrap/child::node()[6] instance of processing-instruction()">Sixth child of wrap should be a pi.</s:assert>
<s:assert test="doc/wrap/child::node()[7] instance of text()">Seventh child of wrap should be a text.</s:assert>
<s:assert test="doc/wrap/child::node()[8] instance of processing-instruction()">Eighth child of wrap should be an pi.</s:assert>
<s:assert test="doc/wrap/child::node()[9] instance of text()">Ninth child of wrap should be a text.</s:assert>
<s:assert test="doc/wrap/child::node()[10] instance of element()">Tenth child of wrap should be an element.</s:assert>
<s:assert test="doc/wrap/child::node()[11] instance of text()">Eleventh child of wrap should be an element.</s:assert>
<s:assert test="doc/wrap/child::node()[12] instance of comment()">Twelfth child of wrap should be a comment.</s:assert>
<s:assert test="doc/wrap/child::node()[13] instance of text()">Thirteenths child of wrap should be a text.</s:assert>
<s:assert test="count(doc/wrap/child::node())=13">Element 'wrap' should have 10 children.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
