difference package:dhall

difference :: Ord k => Map k a -> Map k b -> Map k a
dhall Dhall.Map
Compute the difference of two Maps by subtracting all keys from the second Map from the first Map 
>>> difference (fromList [("C",1),("B",2)]) (fromList [("B",3),("A",4)])
fromList [("C",1)]
difference :: Ord a => Set a -> Set a -> [a]
dhall Dhall.Set
Returns, in order, all elements of the first Set not present in the second. (It doesn't matter in what order the elements appear in the second Set.)