Techniques for reasoning about actions an change in the physical world is one of the classical research topics in artificial intelligence. It is motivated by the needs of autonomous robots which must be able to anticipate their immediate future, to plan their future actions, and to figure out what went wrong in case of problems. It is also motivated by the needs of common-sense reasoning for example in the understanding of natural language texts, where processes and change over time is an ever-present phenomenon. The same set of problems arises in several other areas of computing such as in conceptual modelling for data bases, and in the rapidly growing area of intelligent control. The present research monograph presents and uses a novel methodology for reasoning about actions and change. Traditional research contributions have proposed new logic variants which were only supported by episodical examples. THe work described here uses a systematic methodology for identifying the exact range of applicability of a given logic. For a number of previously proposed logics, as well as for some new ones, the present work characterizes exactly the class where it does not. This book will be a necessary source of reference for researchers in knowledge representation, cognitive robotics, and intelligent control in the years to come. Particularly because of its emphasis on a strict and systematic methodology, it can also be recommended as a textbook for graduate university courses in these areas.

This volume contains revised and extended versions of the papers presented at the Second International Workshop on Non-Monotonic Reasoning, held in Grassau (FRG), June 13-15, 1988. The workshop brought together researchers with different backgrounds, including non-monotonic logic, logic programming, truth maintenance and philosophy. Their papers contain substantial advances to the logical foundations of non-monotonic reasoning, its computational realization, and its application to the formalization of common sense reasoning. The book presents a snapshot of the state of the art in this research area, and provides in-depth discussions of current problems and approaches.