and Motivation -- Basic Definitions and Results -- Abstract Semantics by Size -- Preferential Structures – Part I -- Preferential Structures – Part II -- Higher Preferential Structures -- Deontic Logic and Hierarchical Conditionals -- Theory Update and Theory Revision -- An Analysis of Defeasible Inheritance Systems.

Agents act on the basis of their beliefs and these beliefs change as they interact with other agents. In this book the authors propose and explain general logical tools for handling change. These tools include preferential reasoning, theory revision, and reasoning in inheritance systems, and the authors use these tools to examine nonmonotonic logic, deontic logic, counterfactuals, modal logic, intuitionistic logic, and temporal logic. This book will be of benefit to researchers engaged with artificial intelligence, and in particular agents, multiagent systems and nonmonotonic logic.