We provide a semantic characterization of AGM belief contraction based on frames consisting of a Kripke belief relation and a Stalnaker-Lewis selection function. The central idea is as follows. Let K be the initial belief set and K-A be the contraction of K by the formula A; then B belongs to the set K-A if and only if, at the actual state, the agent believes B and believes that if not-A is (were) the case then B is (would be) the case.

翻译：我们基于由Kripke信念关系和Stalnaker-Lewis选择函数构成的框架，提供了AGM信念收缩的语义刻画。核心思想如下：设K为初始信念集，K-A为K通过公式A进行收缩后的结果；则B属于K-A当且仅当，在实际状态下，主体相信B，并且相信若非A成立则B成立。