Notes on an Approach to Category Theory for Computer Scientists

These notes have been designed for the benefit of theoretical computer scientists who are not sure whether they want to study category theory, and who are too busy to devote the long period of continuous study required to master the subject from standard texts. The notes are therefore structured into three independent chapters, of which the earlier ones are the simplest and most clearly relevant to computer science. Each chapter introduces a number of essential categorical concepts, illustrates them by examples intended to be familiar to computer scientists, and presents theorems describing their most important properties. Each chapter may therefore be studied at widely separated intervals of time; further, the material of each chapter is organised so that there is no need to finish one chapter (or even one section) before starting the next. Finally, the reader who decides to abandon the study of category theory before completing the notes will still have obtained benefit from the effort expended.