Module Set

[Christian Maeder]

> Besides the minimum, also the maximum or the simultaneous splitting of a
> set into its minimum and the remaining set would be useful (for
> recursions).

There's a lot more missing: Test for disjointness, subset-relation as
well as instances for Show and Ord (lexical order, not subset-relation).
Also FiniteMap should have these instances (also for Eq), if the
elements have. These instances would allow nested sets and maps.

Are the sets supposed to be finite, too? (more documentation would help)

Christian