In addition, they appear in algorithms analysis and in the bulk of discrete mathematics taught to computer scientists. This book is devoted to the background of these methods.

Consists of three consecutive parts: 1. Basic Concepts of Computability. 2. Traditional Recursion Theory. 3. Unified Type 2 theory of constructivity and computability on Baire's space including a general the- ory of representations.

These two areas have still huge influence on our lives and our world. The theory of Petri Nets is still developing: some directions of investigations are presented in section 3.

This book, benefiting from the author's research and teaching experience in Algorithmic Information Theory (AIT), should help to make the detailed mathematical techniques of AIT accessible to a much wider audience.

The book presents an overview of the most fundamental aspects of the theory that underlies the Relational Database Model.

In the theory of automata this observation has led to the concepts of pro ducts and complete systems of automata. In the general form of the products of automata all the component automata are fed back to one another.

Consists of three consecutive parts: 1. Basic Concepts of Computability. 2. Traditional Recursion Theory. 3. Unified Type 2 theory of constructivity and computability on Baire's space including a general the- ory of representations.