Is it possible to apply one template
to every first-level node (/ROOT/*) in
a document and have the template output
a mark if the passed node is the first of
its kind?  So that in the example below,
<X a="1"/> would be marked but not <X a="2"/>?

<ROOT>
  <V><W><X a="1"/><X a="2"/><X a="3"/>
</ROOT>

If each node is passed by a general
<xsl:apply-templates/>, I can't use a
position() or *[1] expression.....
No variables so no flagging....

I'm lost.  Should I rewrite my slowly
evolving XML DTD?!