val choose : t -> elt
val hash : t -> int
val equal : t -> t -> bool
+ val uid : t -> int
val positive : t -> set
val negative : t -> set
+ val inj_positive : set -> t
+ val inj_negative : set -> t
end
-module Make : functor (E : Sigs.Set) -> S with type elt = E.elt and type set = E.t
+module Make : functor (E : Ptset.S) -> S with type elt = E.elt and type set = E.t