tcfail032.hs:14: A type signature is more polymorphic than the inferred type Some type variables in the inferred type can't be forall'd, namely: `a{-aG1-}' Possible cause: the RHS mentions something subject to the monomorphism restriction In an expression with a type signature: `x :: _forall_ [a] {PrelBase.Eq a} => a -> PrelBase.Int' Compilation had errors