George Russell wrote:

A minor quibble I know, but every time I use sets I want to add/subtract single elements to/from them. There is no function provided for doing this, so instead you have to do union/delete with a singleton set constructed from the element.

Done. Set now has addToSet :: Ord a => Set a -> a -> Set a delFromSet :: Ord a => Set a -> a -> Set a The names and argument order were chosen to be consistent with FiniteMap, so don't complain :-) Cheers, Simon