DM expressing until-like queries in XPath 2.0

The attached ps file contains an example of an XML document and an
information need which uses an "until" like path (that is, a descendant
path such that all nodes on the path  have a certain attribute-value
true  at them).

I could prove that this query is not expressible in Core XPath (the
"logical core of XPath 1.0" defined by Gottlob et al). 

It is unclear to me if I can express it in XPath 2.0. 
Any help welcome.

Maarten Marx
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Maarten Marx 	    marx@science.uva.nl     http://www.science.uva.nl/~marx

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