- type t
- The type of the elements in the set. - The chosen - tmust be infinite.
 
- val compare : t -> t -> int
- A total ordering function over the set elements. This is a two-argument function - fsuch that:
 - f e1 e2is zero if the elements- e1and- e2are equal,
- f e1 e2is strictly negative if- e1is smaller than- e2,
- and f e1 e2is strictly positive ife1is greater thane2.