One of the fathers of modern logic, German-born mathematician Abraham Fraenkel (1891-1965) first became widely known for his work on set theory. Long fascinated by the pioneering work in set theory of fellow German Ernst Zermelo (1871-1953), Fraenkel launched research to put set theory into an axiomatic setting that improved the definitions of Zermelo's theory and proposed its own system of axioms. Within that system, Fraenkel proved the independence of the axiom of choice. The Zermelo-Fraenkel axioms of set theory, known collectively as ZF, are the standard axioms of axiomatic set theory on which, together with the axiom of choice, all of ordinary mathematics is based. When the axiom of choice is included, the resulting system is known as ZFC.

Studied at Several Universities

Abraham Adolf Fraenkel was born on February 17, 1891, in Munich, Germany. The son of Sigmund and Charlotte (Neuberger) Fraenkel, he was strongly influenced by his...