3 None of the type variable(s) in the constraint `Eq a'
4 appears in the type `Eq Bool'
5 In the type signature for an instance decl
8 None of the type variable(s) in the constraint `Eq a'
9 appears in the type `Int -> Int'
10 In the type signature for `f'
13 None of the type variable(s) in the constraint `Eq a'
14 appears in the type `a -> a'
15 In the type signature for `op'
17 Compilation had errors