[PheonixPharts]

Funnily enough you can't actually implement the proper y-combinator in Haskell because the type system won't allow it. Which is a real shame because in most Lisps you can only implement the applicative order y-combinator due to a lack of lazy evaluation.

[hackyhacky]

What is "improper" about this implementation in Haskel?

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

[lambdas]

The y combinator is used to implement recursion in a language without recursion no?

That definition is dependent on recursion already being present.