The `Set' type

Our implementation of sets (key property: no duplicates) is just a variant of the `FiniteMap' module.

mkSet           :: Ord a => [a]  -> Set a
setToList       :: Set a -> [a]
emptySet        :: Set a
singletonSet    :: a -> Set a

union           :: Ord a => Set a -> Set a -> Set a
unionManySets   :: Ord a => [Set a] -> Set a
intersect       :: Ord a => Set a -> Set a -> Set a
minusSet        :: Ord a => Set a -> Set a -> Set a
mapSet          :: Ord a => (b -> a) -> Set b -> Set a

elementOf       :: Ord a => a -> Set a -> Bool
isEmptySet      :: Set a -> Bool