信念变化与公共知识获得的逻辑表征

如果知识是确证的信念,那么知识的获得就与信念的变化相关。公共知识作为群体知识中最强的知识状态,其获得一方面依赖主体对已有知识(信念)的处理;另一方面依赖主体对行为作用下知识状态改变的处理。知识的处理是一个通过信念的扩充、修正、收缩将初信念集转变为新信念集的过程。这一过程用逻辑术语讲就是通过在知识算子中加入行为算子,再根据条件公共知识的规约公理,达成公共知识的获取。无论是信念的扩充、修正或收缩,还是对规约公理的应用,主体都需要遵守三个原则:知识一致性、信念最小改变和新语句优先选择。

Belief Change and Logical Representation of Acquisition of Common Knowledge

If knowledge is a confirmed belief,then the acquisition of knowledge is related to the change of belief.As the strongest knowledge state in group knowledge,the acquisition of common knowledge depends on the treatment of existing knowledge(belief)by the subject on one hand,and the treatment of knowledge state change under the action of behavior by the subject on the other hand.Knowledge processing is a process of transforming the initial belief set into a new one through the expansion,modification and contraction of belief.In logic terms,this process is achieved by adding behavior operators to knowledge operators,and then following the reduction axiom of conditional common knowledge.Whether it be the expansion,modification or contraction of belief,or the application of the reduction axiom,the subject needs to abide by three principles:knowledge consistency,belief minimum change and new sentence priority.