<?xml version="1.0" encoding="UTF-8"?>
<x>
 <y>
   <z/>
 </y>
</x>

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:template match="/">
 <xsl:apply-templates select="x" />
</xsl:template>

<xsl:template match="x">
 <xsl:if test=".//z">
   x is ancestor of z
 </xsl:if>
</xsl:template>

If this is a general XPath question, then I think above could be the
appropriate answer.

If you need to do something specific, please let us know. There could
be other explanations.

Hello,

alas, I cannot see any way to check whether a given node is an ancestor of a
given other node in XPath.  How do I do this?

Best wishes,
Wolfgang

--
Regards,
Mukul Gandhi