ABSTRACT
A prime reason for the increase in importance of mathematical logic in the twentieth century was the discovery of the paradoxes of set theory and the need for a revision of intuitive (and contradictory) set theory. Many different axiomatic theories have been proposed to serve as a foundation for set theory but, no matter how they may differ at the fringes, they all have as a common core the fundamental theorems that mathematicians require for their daily work. We make no claim about the superiority of the system we shall use except that, from a notational and conceptual standpoint, it is a convenient basis for present-day mathematics.
