{-# htermination (signumRatio :: Ratio MyInt -> Ratio MyInt) #-} import qualified Prelude data MyBool = MyTrue | MyFalse data List a = Cons a (List a) | Nil data MyInt = Pos Nat | Neg Nat ; data Nat = Succ Nat | Zero ; data Ordering = LT | EQ | GT ; data Ratio a = CnPc a a; fromIntMyInt :: MyInt -> MyInt fromIntMyInt x = x; primEqNat :: Nat -> Nat -> MyBool; primEqNat Zero Zero = MyTrue; primEqNat Zero (Succ y) = MyFalse; primEqNat (Succ x) Zero = MyFalse; primEqNat (Succ x) (Succ y) = primEqNat x y; primEqInt :: MyInt -> MyInt -> MyBool; primEqInt (Pos (Succ x)) (Pos (Succ y)) = primEqNat x y; primEqInt (Neg (Succ x)) (Neg (Succ y)) = primEqNat x y; primEqInt (Pos Zero) (Neg Zero) = MyTrue; primEqInt (Neg Zero) (Pos Zero) = MyTrue; primEqInt (Neg Zero) (Neg Zero) = MyTrue; primEqInt (Pos Zero) (Pos Zero) = MyTrue; primEqInt vv vw = MyFalse; esEsMyInt :: MyInt -> MyInt -> MyBool esEsMyInt = primEqInt; primCmpNat :: Nat -> Nat -> Ordering; primCmpNat Zero Zero = EQ; primCmpNat Zero (Succ y) = LT; primCmpNat (Succ x) Zero = GT; primCmpNat (Succ x) (Succ y) = primCmpNat x y; primCmpInt :: MyInt -> MyInt -> Ordering; primCmpInt (Pos Zero) (Pos Zero) = EQ; primCmpInt (Pos Zero) (Neg Zero) = EQ; primCmpInt (Neg Zero) (Pos Zero) = EQ; primCmpInt (Neg Zero) (Neg Zero) = EQ; primCmpInt (Pos x) (Pos y) = primCmpNat x y; primCmpInt (Pos x) (Neg y) = GT; primCmpInt (Neg x) (Pos y) = LT; primCmpInt (Neg x) (Neg y) = primCmpNat y x; compareMyInt :: MyInt -> MyInt -> Ordering compareMyInt = primCmpInt; esEsOrdering :: Ordering -> Ordering -> MyBool esEsOrdering LT LT = MyTrue; esEsOrdering LT EQ = MyFalse; esEsOrdering LT GT = MyFalse; esEsOrdering EQ LT = MyFalse; esEsOrdering EQ EQ = MyTrue; esEsOrdering EQ GT = MyFalse; esEsOrdering GT LT = MyFalse; esEsOrdering GT EQ = MyFalse; esEsOrdering GT GT = MyTrue; gtMyInt :: MyInt -> MyInt -> MyBool gtMyInt x y = esEsOrdering (compareMyInt x y) GT; otherwise :: MyBool; otherwise = MyTrue; signumReal0 x MyTrue = fromIntMyInt (Neg (Succ Zero)); signumReal1 x MyTrue = fromIntMyInt (Pos (Succ Zero)); signumReal1 x MyFalse = signumReal0 x otherwise; signumReal2 x MyTrue = fromIntMyInt (Pos Zero); signumReal2 x MyFalse = signumReal1 x (gtMyInt x (fromIntMyInt (Pos Zero))); signumReal3 x = signumReal2 x (esEsMyInt x (fromIntMyInt (Pos Zero))); signumReal x = signumReal3 x; signumMyInt :: MyInt -> MyInt signumMyInt = signumReal; signumRatio :: Ratio MyInt -> Ratio MyInt signumRatio (CnPc x y) = CnPc (signumMyInt x) (fromIntMyInt (Pos (Succ Zero)));