Please, how to correctly set an explicit type for a local value in the body of a polymorphic function? Example (tested under ghc-7.6.1): data D a = D1 a | D2 a (a -> a) f :: Eq a => D a -> a f (D1 x) = x f (D2 x g) = let -- y :: Eq a => a y = g x in if x == y then x else g y main = putStr $ shows (f (D2 (1 :: Int) succ)) "\n" This is compiled by ghc --make Main Now I need, for a certain reason, to explicitly set the type for y in `let', with the meaning: "this very `a' which is in the signature for f" (and I think that this type Haskell assignes to y in "y = g x"). I need to declare this type in a separate line: y :: <what ever it is>. Both `y :: a' and `y :: Eq a => a' are not compiled. Please, copy the answer to mechvel@botik.ru Thanks, ------ Sergei