Abstract

Belief revision is a dynamic, evolving research topic. This theme includes a large number of different backgrounds, different patterns of theory. A Erluo if , Gardner Fox and Meijin Sen jointly established by the belief revision theory is one of the relatively early formation, the most influential theory. This article describes the basic concepts of belief revision and review of the AGM theory. The problem of belief revision is a lively subject, which contains various theories. The theory conceived by CE Alchourron, P. Gardenfors and D. Markinson is of special important. In this essay we outline The AGM theory and state its approach