{-# htermination (elemMyBool :: MyBool -> (List MyBool) -> MyBool) #-} import qualified Prelude data MyBool = MyTrue | MyFalse data List a = Cons a (List a) | Nil map :: (a -> b) -> (List a) -> (List b); 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 :: (c -> a) -> (b -> c) -> b -> a; pt f g x = f (g x); any :: (a -> MyBool) -> (List a) -> MyBool; any p = pt or (map p); esEsMyBool :: MyBool -> MyBool -> MyBool esEsMyBool MyFalse MyFalse = MyTrue; esEsMyBool MyFalse MyTrue = MyFalse; esEsMyBool MyTrue MyFalse = MyFalse; esEsMyBool MyTrue MyTrue = MyTrue; elemMyBool :: MyBool -> (List MyBool) -> MyBool elemMyBool = pt any esEsMyBool;