[Haskell] Re: Syntax Q: How do you share RHS's in case expressions!?

I'm baffled that I can't find anywhere in the documentation how to associate two or more patterns with the same right-hand-side...

It gets more interesting with things like: case x of ( ([],a) | (a,[]) ) -> .. a .. where the rewrite looks like: let foo a = ... in case x of ([],a) -> foo a; (a,[]) -> foo a :-( Stefan