[Haskell-beginners] [OT] To Mock A Mockingbird

Hi all, I've been reading the book "To Mock A Mockingbird" by Robert Smullyan recently and I don't get the part about the birds at all. I think I understand that a bird is a function, but what would it's type be in Haskell? It says that birds hear a call and answer by another call, so I thought String -> String or something like that. But if you have a mockingbird that can answer what a bird would answer to itself, that means that it's input must contain the other bird... Do all the birds have the same type? Thanks, Patrick -- ===================== Patrick LeBoutillier Rosemère, Québec, Canada