int isSetsEqual (set *, set *);
set *subtractFromSet (set *, set *, int);
int elementsInSet (set *);
+void *indexSet(set *, int);
set *intersectSetsWith (set *, set *, int (*cFunc) (void *, void *), int);
int isSetsEqualWith (set *, set *, int (*cFunc) (void *, void *));
void *peekSet (set *);