Please, discard this question. It was my fault, the compare function was a partial order instead of a total order. Best, Walter Jean-Philippe Bernardy wrote:

I'd say your compare function isn't transitive.

If you can tell it's well behaved, and if you can send me even your complicated example, I'll look into it.

Cheers, JP.

On 1/21/06, Walter Moreira wrote:

...

Hello list. Are there situations where a set can contain duplicate elements?

I have a newtype and it is an instance of 'Eq' via the 'compare' method, and it is also an instance of 'Ord'. After some Data.Set operations with sets of that type I get a set which contains two elements which compare equal. What am I doing wrong?

The function 'Set.valid' returns 'False' when applied to the set. I use the function 'Set.fromList' sometimes. Is it supposed to always yield a valid set? or it may depend on the order or equality?

Sorry the question is a little vague. When I try to construct small examples the problem disappear.

Thanks, Walter _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell