{-# htermination (negateMyInt :: MyInt  ->  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 ;

primNegInt :: MyInt  ->  MyInt;
primNegInt (Pos x) = Neg x;
primNegInt (Neg x) = Pos x;

negateMyInt :: MyInt  ->  MyInt
negateMyInt = primNegInt;