Michael Barr, Charles Wells.
Category Theory for Computing Science.
Prentice Hall. 1990
Category Theory for Computing Science is a textbook in category theory
written for researchers im theoretical computing science
and for postgraduate and advanced undergraduate students
in computing science and mathematics.
The book expounds the basic ideas and constructions of category theory,
with examples from and applications to computing science.
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.
