ABSTRACT
Typically a definition in mathematics defines a new term in terms of older terms that have already been treated. But there must be a collection of "first terms" which are not defined in terms of earlier terms. These are the undefinables. In modern mathematics it is customary to use "set" and "element of" as undefinables. A set is declared to be a collection of objects. All of modern mathematics is formulated in the language of sets and functions. It was Georg Cantor who laid the foundations for modern set theory. The Venn diagram is a pictorial device for depicting relationships among sets. While a Venn diagram is certainly not a rigorous proof, it is a useful means for understanding mathematical ideas. This chapter develops the basic ideas of set theory, which includes set-theoretic product and the power set. Cantor showed us that the power set operation is a useful device for producing arbitrarily large sets.
