Knowledge and communication: a tutorial
Yoram Moses · 1992
The subtle interaction between knowledge, action, and communication is an important theme underlying much of the literature on reasoning about knowledge in a variety of disciplines. The purpose of this paper is to review work on the relationship between knowledge and communica-tion in distributed systems. Communication is the basic means by which knowledge is obtained and transferred in a distributed system. As a result, properties of the communication medium play a central role in determining what states of knowledge can result from communication. Most of this paper is a review of theorems that illustrate this connection and a discussion of their implications. In the latter part of this paper, we consider knowledge-oriented programming, a novel approach to describing agents ' behavior in a distributed system. Knowledge-oriented programs are an extension of the knowledge-based protocols of Halpern and Fagin, in which communication is abstracted away completely from the description of agents ' behavior. In its stead, agents can perform high level actions that are defined in terms of changing the state of knowledge of other agents. Such actions are called knowledge-oriented actions. Communication then enters when we come to implement the knowledge-oriented actions in a given context. Knowledge-oriented programming makes explicit use of the fact that the role of communication is to change the state of knowledge of agents in the system. 1