The joy of sets: Fundamentals of contemporary set theory (Undergraduate texts in mathematics)

This treatise is intended to provide an account of those parts of contemporary set theory that are relevant to other areas of pure mathematics. Aimed at advanced undergraduates and beginning graduate students, the text is written in an easy-going style, with a minimum of formalism. The book begins with a review of "naive" set theory. It then develops the Zermelo-Fraenkel axioms of the theory, showing how they arise naturally. After discussing the ordinal and cardinal numbers, the book then delves into contemporary set theory, covering such topics as: the Borel hierarchy, stationary sets and regressive functions, and Lebesgue measure. Two chapters present an extension of the Zermelo-Fraenkel theory, discussing the axiom of constructibility and the question of probability in set theory. A final chapter presents an account of an alternative concept of set theory that has proved useful in computer science, the non-well-founded set theory of Peter Aczel.