Introduction

Abstract

In Sections 1–6 we summarize for the reader’s convenience some basic material with which he is assumed to be thoroughly familiar (with the possible exception of the distinction between sets and proper classes (Section 2), the characterization of the Cartesian product by a universal mapping property (Theorem 5.2) and the Recursion Theorem 6.2). The definition of cardinal number (first part of Section 8) will be used frequently. The Axiom of Choice and its equivalents (Section 7) and cardinal arithmetic (last part of Section 8) may be postponed until this information is actually used. Finally the reader is presumed to have some familiarity with the fields Q, R, and C of rational, real, and complex numbers respectively.