-- Elementare Prädikate
s == t
s < t
-- Zusammengesetzte Prädikate
not p
p && q
p || q
p => q Axiome für Map
lookup a (empty :: Map Int String) == Nothing
lookup a (insert a v (s :: Map Int String)) == Just v
lookup a (delete a (s :: Map Int String)) == Nothing
a /= b ==> lookup a (insert b v s) == lookup a (s :: Map Int String)
a /= b ==> lookup a (delete b s) == lookup a (s :: Map Int String)