> <xsl:variable name="Xml" as="document-node()"> <xsl:document> 
> <xsl:sequence select="document('file.xml')"/> </xsl:document> 
> </xsl:variable>
> 

You definitely don't wan't to do that. You're loading an external document
and then making a copy of it. You don't need to make a copy: use the
original instead!

Michael Kay
http://www.saxonica.com/