(<- (Intersection @Sets)
(Setofall ?X
(Exists (?S)
(=> (Item ?S (Listof @Sets)) (Member ?X ?S)))))
(Instance-Of (Arity Intersection) Undefined)
(=> (Intersection $X $Y) (Set $Y))
(=> (= (Intersection @Sets) ?Set)
(=> (Item ?S (Listof @Sets)) (Set ?S)))
(<=> (Disjoint ?S1 ?S2) (Empty (Intersection ?S1 ?S2)))
(Instance-Of (Intersection @Sets) Empty)
(Empty (Intersection @Sets))
(<=> (Mutually-Disjoint @Sets) (Empty (Intersection @Sets)))
(=> (And (Bounded ?U) (Set ?S)) (Bounded (Intersection ?U ?S)))