haskell - Unifying c -> a -> b and (a -> b) -> c

Question

What is the type inferred by a Haskell type synthesizer when unifying the types c -> a -> b and (a -> b) -> c?

Can someone explain me how can I solve it?

Thanks!

Answer 1

This seems to be some kind of exercise/homework so I will not spoil everything but give you some hints first:

• the type c -> a -> b is actually c -> (a -> b)
• so you have to unify c -> (a -> b) with (a -> b) -> c, that is:
  • c with a -> b (first part)
  • a -> b with c (second part)

now what could that (try to get rid of c ;) ) be now?

PS: I am assuming you want those types a, b, .. to be the same