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Using just this axiom, the author easily derives four standard axioms of Zermelo-Fraenkel set theory, namely, the axioms of separation, power set, union, and pairing, axioms which, because of the unacceptability of an abstraction axiom, are normally posited individually. The further power of the "Mengenbildungsaxiom" is shown by the possiblity of deriving as a theorem 3y Vx(x c y «-> x g a), which guarantees the existence for arbitrary a of the set t *(o), and hence of the transitive closure of any set. BEDE RUNDLE