A Planner for Reasoning about Knowledge and Action

This paper reports recent results of research on planning systems that have the ability to deal with multiple agents and to reason about their knowledge and the actions they perform. The planner uses a knowledge representation based on the possible worlds semantics axiomatization of knowledge, belief and action advocated by Moore [5]. This work has been motivated by the need for such capabilities in natural language processing systems that will plan speech acts and natural language utterances [1, 2]. The sophisticated use of natural language requires reasoning about other agents, what they might do and what they believe, and therefore provides a suitable domain for planning to achieve goals involving belief. This paper does not directly address issues of language per se, but focuses on the problem-solving requirements of a language-using system, and describes a working system, kamp (Knowledge And Modalities Planner), that embodies the ideas reported herein.