In this paper we investigate AGM belief contraction operators by using the tools of algebraic logic. We generalize the notion of contraction to arbitrary finitary propositional logics, and we show how to switch from a syntactic-based approach to a semantic one. This allows to build a solid bridge between the validity of AGM postulates in a propositional logic and specific algebraic properties of its intended algebraic counterpart. Such a connection deserves particular attention when we deal with maxichoice contractions, as studied in the final part of the paper.

中文翻译：

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关于 AGM 信念收缩理论的逻辑代数方法

在本文中，我们使用代数逻辑工具研究了 AGM 信念收缩算子。我们将收缩的概念推广到任意有限命题逻辑，并展示了如何从基于句法的方法转换为语义方法。这允许在命题逻辑中 AGM 假设的有效性与其预期代数对应物的特定代数属性之间建立牢固的桥梁。正如本文最后部分所研究的那样，当我们处理最大选择收缩时，这种联系值得特别注意。