ABSTRACT
Preamble: This short chapter is composed of very basic and very easy material, likely familiar to most readers in one form or other, but we record it here for later reference and to fix notation and terminology. Only very modest specific knowledge is required of the prospective reader. What is really expected of the reader is a level of mathematical maturity comparable to that fostered by books like Ahlfors [4, 5 Normal families, pp. 219–227], Greene and Krantz [91, Chapter 6], Marshall [185, Chapter 10.1], Gunning and Rossi [98, pp. 10–12], and Narasimhan [218, pp. 7–11], but we by no means require a mastery of the contents of these outstanding classics.
