comparing two xpath fragment with xslt1.0

Hi all,
Should everyone known how to compare two xpath fragments P1 and P2 with 
xslt?
Precisely how to determine equivalence between P1 and p2? This means that a 
nodes set selected by P1 is equal to the nodes Set selected by P2.
I thanks all of you in advance.

regards

Majirus

_________________________________________________________________
Hotmail : bientôt 250 Mo de stockage ! 
http://www.imagine-msn.com/hotmail/fr-fr/