g 0 []     = 0
g _ (x:xs) = x

h x = h x

-- The evaluation of `m` terminates in Curry but not in Haskell:
m = g (h 0) [1]


-- flexible not (as Prelude.not):
fnot :: Bool -> Bool
fnot False = True
fnot True  = False

-- rigid not:
rnot :: Bool -> Bool
rnot x = case x of False -> True
                   True  -> False