A Set-Class all of whose instances are sets whose members are all of Class Product.
(=> (Set-Of-Products ?Products) (Forall (?X) (=> (Member ?X ?Products) (Product ?X))))
(<=> (Set-Of-Products ?Products) (And (Eo-Set ?Products) (Set ?Products) (Forall (?X) (=> (Member ?X ?Products) (Product ?X)))))