please find attached patch to current CVS ( contrib/ltree )

Changes:

July 31, 2002
   Now works on 64-bit platforms.
   Added function lca - lowest common ancestor
   Version for 7.2 is distributed as separate package -
   http://www.sai.msu.su/~megera/postgres/gist/ltree/ltree-7.2.tar.gz

Oleg Bartunov