I think that your compare function has the result inverted, you could try: between a b x | x < a = GT | x > b = LT | otherwise = EQ I think that the tree is correct. On Fri, 2010-09-17 at 08:41 +0100, Stephen Tetley wrote:
Hello Alexander
I suspect mydelete' isn't working because it needs a "sorted" tree - either the initial tree you are supplying isn't sorted or it becomes unsorted after one delete step.
I don't know the AVL library at all (I only installed it now to look at your problem) so I can't say from looking at the constructors whether the problem tree is malformed, the problem tree being:
P (Z E 1 E) 3 E
Potentially very few people use the Avl module which is why you haven't had a reply yet. You could try posting to the Cafe instead if you don't get a better answer.
Best wishes
Stephen _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners