[xsl] axes in XPath patterns

["Birnbaum, David J djbpitt@xxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Dear XSL-list,

If I9ve understood correctly, the only axes supported in an XPath pattern
in XSLT 2.0 are the child and the attribute axes. For that reason, a
construction like:

	<xsl:template match="paragraph/descendant::inner">

should raise an error, as it does in <oXygen/>. But I was surprised to see
that the following construction:

	<xsl:template match="paragraph//inner">

does not raise an error in <oXygen/>. According to Michael Kay, p. 627,
paragraph//inner should be equivalent to
paragraph//descendant-or-self::node()/child::inner, so it does appear to
use an axis other than the child or attribute axis.

I don't know how to reconcile this discrepancy with the general
prohibition against using axes other than child or attribute in an XPath
pattern in XSLT 2.0. Shouldn't both of the patterns above raise the same
type of error?


Thanks,

David