{-# htermination (elemChar :: Char  ->  (List Char)  ->  MyBool) #-} 
import qualified Prelude 
data MyBool = MyTrue | MyFalse 
data List a = Cons a (List a) | Nil 
data Char = Char MyInt ;

data MyInt = Pos Nat  | Neg Nat ;

data Nat = Succ Nat  | Zero ;

map :: (b  ->  a)  ->  (List b)  ->  (List a);
map f Nil = Nil;
map f (Cons x xs) = Cons (f x) (map f xs);

foldr :: (a  ->  b  ->  b)  ->  b  ->  (List a)  ->  b;
foldr f z Nil = z;
foldr f z (Cons x xs) = f x (foldr f z xs);

pePe :: MyBool  ->  MyBool  ->  MyBool;
pePe MyFalse x = x;
pePe MyTrue x = MyTrue;

or :: (List MyBool)  ->  MyBool;
or = foldr pePe MyFalse;

pt :: (b  ->  c)  ->  (a  ->  b)  ->  a  ->  c;
pt f g x = f (g x);

any :: (a  ->  MyBool)  ->  (List a)  ->  MyBool;
any p = pt or (map p);

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;

primEqChar :: Char  ->  Char  ->  MyBool;
primEqChar (Char x) (Char y) = primEqInt x y;

esEsChar :: Char  ->  Char  ->  MyBool
esEsChar = primEqChar;

elemChar :: Char  ->  (List Char)  ->  MyBool
elemChar = pt any esEsChar;