*Category Theory for Computing Science*. 1990, with Michael Barr- [
*Category Theory for Computing Science: 3rd edn*.] 2012, with Michael Barr

The emphasis is on examples and on understanding the concepts rather than on formal proofs of the theorems. Extensive references are given for proofs and further development for each topic. The book is arranged with many of the later chapters independent of each other. Most sections have exercises that provide additional examples of the concepts and pursue certain topics further. Solutions to all the exercises are provided.

available from https://www.researchgate.net/publication/259237270_Category_Theory_for_Computing_Science