Bücher der Reihe Monographs in Theoretical Computer Science. An EATCS Series

Net theory is a theory of systems organization which had its origins, about 20 years ago, in the dissertation of C. The main concern of this book is the presentation of those parts of net theory which can serve as a basis for practical application. By generali zation of these notions a part of the theory of nets is presented.

Other approaches based on partially ordered sets - such as the theory of traces, the theory of event structures and the theory of semi words - are not considered in this book, in spite of the strong links between them and net theory.

At least four research fields detennine the theoretical background of specification and deduction in computer science: recursion theory, automated theorem proving, abstract data types and tenn rewriting systems.

The mathematical theory of computation has given rise to two important ap proaches to the informal notion of "complexity": Kolmogorov complexity, usu ally a complexity measure for a single object such as a string, a sequence etc., measures the amount of information necessary to describe the object.