Modelling rational agents in a dynamic environment: Putting humpty dumpty together again

Abstract

In this paper we propose a formal framework to model rational agents. We distinguish four levels where aspects of agency are situated, viz. the informational, action, motivational and social level. On these levels we consider concepts like knowledge and belief of agents, opportunities for, and results of actions that they may perform, preferences, goals, intentions and commitments, and speech acts. The language describing these concepts is a multi-modal one, and the models used to interpret this language are Kripke-style possible worlds models. Both the language and the models are defined in a rigorously formal way, while the actual semantics are only sketched. We conclude this paper with a brief comparison with related work on the formalisation of rational agents.