Introduction

Abstract

Reversible computing is a paradigm that has a close relation to physical reversibility. Since microscopic physical laws are reversible, and future computing devices will surely be implemented directly by physical phenomena in the nano-scale level, it is an important problem to know how reversibility can be effectively utilized in computing. Reversible computing systems are defined as systems for which each of their computational configurations has at most one predecessor. Hence, they are “backward deterministic” systems. Though the definition is thus rather simple, these systems reflect physical reversibility very well, and they are suited for investigating how computing systems can be realized in reversible physical environments. In this chapter, we argue reversibility in physics and computing, the significance of reversible computing, and the scope of this volume. Various models of reversible computing ranging from a microscopic level to a macroscopic one are dealt with from the viewpoint of the theory of automata and computing. Terminologies and notations on logic, mathematics, and formal languages used in this volume are also summarized.