[xml] xpointer xmlns() scheme?

["Bob Stayton" <bobs sagehill net>]

I'm a big fan of XInclude, and I use xmllint and xsltproc extensively 
because they support the xpointer() scheme of XInclude.  I recently tried 
to process some DocBook5 documents which are in the docbook namespace, and 
I'm not having much luck.  It seems the xmlns() scheme must be specified as 
part of the xpointer attribute for the include element, but it doesn't seem 
to work in libxml2.

<xi:include href="booktest5.xml"
 xpointer="xmlns(db=http://docbook.org/ns/docbook) 
xpointer(//db:dedication)"
 xmlns:xi="http://www.w3.org/2001/XInclude"/>

Am I doing something wrong, or is xmlns() not supported with the xpointer 
scheme?

Bob Stayton
Sagehill Enterprises
DocBook Consulting
bobs sagehill net