XSL2, currently using Saxon 10 HE as the XSL processor, with its default
XML parser

I'm trying to add a couple of fixed attributes to my XML schema so that
I can simplify a number of long-winded tests in some of my transforms.

So for example I modified the schema so that a large number of\xA0 elements
include

<xs:attribute name="block" fixed="Y" />

in their definition. (Extensions mean this is a one-liner edit to the
XSD, hooray).

I'm sure you know what's coming next :-(

I was hoping that this would allow something like this in my XSL:

<xsl:choose>
\xA0 <xsl:when test="ancestor::*[@block = 'Y']"> ... </xsl:when>
\xA0 <xsl:otherwise> ... </xsl:otherwise>
</xsl:choose>

instead of having an enormous qualifier explicitly testing dozens of
possible element names.

So this isn't working. I can see that I need a Saxon EE license for
"full schema-awareness", but so far as I can tell this isn't a question
of full schema awareness in the XSL processor, but a requirement for an
XML parser which recognises the fixed attributes. I may be interpreting
the Saxon documentation naiively, but it looks to me as though I should
be able to achieve what I want within Saxon HE so long as I have an
appropriate parser (and apparently this is not the default used by
Saxon). Is there such a parser available?

I do have the last resort option of transforming all of the documents so
that these attributes are included in-place in the XML, but I'm hoping I
don't need to do that.\xA0

Is there a way to achieve what I want or is a Saxon EE license the only
way to get there?

cheers
T\xA0