author : Matthew Hennessy

The book is unique in developing three complementary views of the semantics of concurrent processes: a behavioral view, in which processes are deemed to be equivalent if they cannot be distinguished by any experiment; a denotational model, in which processes are interpreted as certain kinds of trees; and a proof-theoretic view, in which processes may be transformed into equivalent processes using valid equations or transformations. Hennessy’s book is an excellent guide on how to reason about and relate behavioral, denotational, and proof-theoretical aspects of languages in general: All three views are developed for a sequence of increasingly complex algebraic languages for concurrency, and in each case they are shown to be equivalent.

Algebraic Theory of Processes is a valuable source of information for theoretical computer scientists. It is an elegant and comprehensive introduction not only to the field but also to the author’s own theory of the behavioral semantics of processes (“testing equivalence”) and original results in example languages for distributed processes. It is self-contained; the problems addressed are motivated from the standpoint of computer science, and all the required algebraic concepts are covered. There are exercises at the end of each chapter.