Fixed point combinator for mutually recursive functions?

Question

Is there a fixed point combinator for creating tuples of mutually recursive functions? I.e. I\'m looking for something like the Y-Combinator but which takes multiple \"recu

Answer 1

I'm not entirely sure about this one. I'm still trying to find a formal proof of it. But it seems to me you don't need one. In Haskell, if you have something like:

fix :: (a -> a) -> a
fix f = let x = f x in x

main = let { x = ... y ...; y = ... x ... } in x

you can rewrite main to

main = fst $ fix $ \(x, y) -> (... y ..., ... x ...)

But like I said, I'm not 100% sure about this one.