关键词: 不完备形式背景, 近似概念, 相容概念, 相容规则

Abstract: This paper，according to the theory of formal concept analysis，mainly discusses the tolerant concept of incomplete formal context and the acquisition method of tolerant rules based on it，as well as provides a corresponding construction algorithm.In order to compress large-scale set of tolerant rules，the paper puts forward an inference rule to reduce the redundant tolerant rules，so that a complete and non-redundant set of tolerant rules can be got.Users can take this method into various practical needs through setting parameters.Example proves the method is effective.The paper not only provides a new approach for handling the incomplete formal context，but also lays the foundation for the in-depth study.

Key words: incomplete formal context, approximate concepts, tolerant concepts, tolerant rules