中文摘要：

在研究了概念格形成的偏序结构的基础上，引进了由两个形式背景形成的决策形式背景，讨论了外延集类上等价关系和交一致关系，给出了决策形式背景下规则提取与属性约简方法．同时对于在规则约简中起不同作用的属性，区分了核心（存在于任何约简中）、相对必要属性（存在于某些约简中）和不必要属性（不存在于任何约简中），给出了各类属性的特征和判别方法．这些方法为概念格规则提取的启发式算法打下了基础．

英文摘要：

A decision formal context combined with two formal contexts is introduced based on studying partial ordered structures in concept lattices. Equivalent relations and consistent meet relations on sets of extension are discussed. By these analysis, approaches to rule acquisitions and attribute reductions on a decision formal context are established. Meanwhile, different kinds of attributes which play different roles during rule acquisitions are distinguished. Characters and judgment theorems of core attributes existing in any reductions and unnecessary attributes not existing in any attribute reductions are given. These approaches lay basis for heuristic algorithms of rule acquisitions in concept lattices.