Mathematician
Fraenkel's early work was on Kurt Hensel's p-adic numbers and on the theory of rings. He is best known for his work on axiomatic set theory, publishing his first major work on the topic ("Einleitung in die Mengenlehre") in 1919. In 1922 and 1925, he published two papers that sought to improve Zermelo's axiomatic system; the result is the Zermelo–Fraenkel axioms. Fraenkel worked in set theory and foundational mathematics.
Fraenkel also was interested in the history of mathematics, writing in 1920 and 1930 about Gauss' works in algebra, and he published a biography of Georg Cantor. After retiring from the Hebrew University and being succeeded by his former student Abraham Robinson, Fraenkel continued teaching at the Bar Ilan University in Ramat Gan (near Tel Aviv).
Read more about this topic: Abraham Fraenkel