3 A type signature is more polymorphic than the inferred type
4 Can't for-all the type variable(s) `aO3'
5 in the type `(aNZ -> aNX aO3) -> aNX aO3'
6 In the first argument of `KContT', namely `(\ cont' -> cont a)'
7 In the first argument of `f', namely
8 `(\ a -> KContT (\ cont' -> cont a))'
9 In the first argument of `unKContT', namely
10 `(f (\ a -> KContT (\ cont' -> cont a)))'
13 Compilation had errors