<schema xmlns="http://www.ascc.net/xml/schematron" >
<pattern name="Test count">
<rule context="/*">
<report test="count(//BBB) = count(//AAA)">O.K.</report>
<assert test="count(//BBB) <= count(//AAA)">Some AAA are missing</assert>
<report test="count(//BBB) < count(//AAA)">Some BBB are missing</report>
</rule>
</pattern>
</schema>