[XSLT2.0] xml:base interaction

Hello all,
 
I am finding the xml:base interaction with xslt 2.0 to be a bit vague,
as its is defined in the context of the construction of sequences and
result or temporary trees. Might be useful to have at least one example
on stylesheet element, as well as clarifying text with respect to the
following elements;
 
xsl:include
xsl:import
xsl:result-document
 
and possibly xsl:function ???
 
regards, Jim Fuller