]> let rec (@) l1 l2 = match l1 with [] -> l2 | hd :: tl -> hd :: (tl @ l2) The O'Caml implementation of (@) is recursive and not tail-recursive. All one really has to do during "append" is copy l1 and set the last element's CDR to l2. I can see why this can not be done in O'Caml itself, but since (@) is such a common operation, I'm wondering why it was decided to implement it inefficently in O'Caml itself? Cheers, Oleg ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners