ABSTRACT
In this appendix we give an overview of those aspects of elementary set theory that are used throughout the book. For details the reader may wish to consult [2, 8].
Notation for a Set A set is simply a collection of objects, each of which is called a member or
element of the set. Sets are usually denoted by capital letters, and members of a set by small letters. If x is a member of the set A, we write x ∈ A; otherwise, we write x 6∈ A. The empty set, denoted by ∅, is the set with no members.
