This collection of papers is the outcome of the work of a community of researchers in AI who, during the last twenty years, have developed the logical formalisms and methods for characterizing intelligent behaviors of agents, knowledge-based systems and processes in terms of reasoning about the environment, actions, and activities that are capable of changing the current state. The book deals with commonsense reasoning, in particular with Reiter's Default Logic formalism, the theory of actions and reasoning about actions, including formalisms for high-level robot control, and different approaches to knowledge representation, all based on symbolic logic.
