IOS Press Knowledge-Based Asynchronous Programming

Abstract. A knowledge-based program is a high-level description of the behaviour of agents in terms of knowledge that an agent must have before (s)he may perform an action. The definition of the semantics of knowledge-based programs is problematic, since it involves a vicious circle; the knowledge of an agent is defined in terms of the possible behaviours of the program, while the possi-ble behaviours are determined by the actions which depend on knowledge. We define the semantics of knowledge-based programs via an iteration approach generalizing the well-known fixpoint con-struction. We propose a specific iteration as the semantics of a knowledge-based program, and justify our choice by a number of examples, including the Unexpected Hanging Paradox