Foundation Material

Abstract

In this chapter, we recall some results from elementary group theory, number theory, and approximation theory. In doing so, we also establish notation that will be used consistently throughout the rest of the text.

The symbol |S| denotes the size of S. For example, if S is a finite set, then |S| is the number of elements in S; if z is a complex number, then |z| is the modulus (or absolute value) of z; and if f is a complex-valued function defined on a set S, then |f| is the function (defined on the same set) whose value at a point s є S is |f(s)|.