insertOrDelete :: Ord a => a -> Bool -> Set a -> Set a
insertOrDelete = \key insert set -> ((ifElse insert Set.insert Set.delete) key set)
insertOrDelete :: Ord a => a -> Bool -> Set a -> Set a
insertOrDelete = \key insert set -> ((ifElse insert Set.insert Set.delete) key set)
insertOrDelete = \key insert set -> ((ifElse insert Set.insert Set.delete) key set)