Inappropriate use of XML Namespaces in XQuery, XPath 2.0 and XSLT 2.0?

In the various draft XQuery, XPath 2.0 and XSLT 2.0 documents it is indicated 
that datatypes and functions are contained in designated XML namespaces. A 
similar seeming error made in W3C XML Schema is also carried forward into the 
XQuery/XPath/XSLT2 documents.

This seems to me to be in conflict with the Namespaces in XML 1.0 
Recommendation which defines an XML namespace as applying to element type names and 
attribute names. There is no provision that I can see in the Namespaces in XML Rec 
for datatype or function names being part of an "XML namespace".

Correcting this seeming discrepancy should be straightforward but it seems to 
me that it needs to be tidied.

Andrew Watt