{-# htermination (realToFrac :: Ratio MyInt -> Ratio MyInt) #-} import qualified Prelude data MyBool = MyTrue | MyFalse data List a = Cons a (List a) | Nil data Integer = Integer MyInt ; data MyInt = Pos Nat | Neg Nat ; data Nat = Succ Nat | Zero ; data Ratio a = CnPc a a; fromIntegerMyInt :: Integer -> MyInt fromIntegerMyInt (Integer x) = x; fromRational (CnPc x y) = CnPc (fromIntegerMyInt x) (fromIntegerMyInt y); pt :: (c -> a) -> (b -> c) -> b -> a; pt f g x = f (g x); toIntegerMyInt :: MyInt -> Integer toIntegerMyInt x = Integer x; toRational (CnPc x y) = CnPc (toIntegerMyInt x) (toIntegerMyInt y); realToFrac = pt fromRational toRational;