论域约简是指对决策表对象集合的压缩。
Universe reduction refers to the compression of object set in decision table.
首先分析对比较为成熟的属性约简算法的优缺点，提出论域缩减的方法。
Firstly, we put forward an improved domain reduction method on the basis of analyzing the attribute reduction algorithm of the current information system.
以粗糙逻辑为基础，首先给出了在新实例加入论域后判断约简变化与否以及判断原极小决策算法中决策规则变化与否的判定依据。
Based on rough logic, theorems is presented, whether attribute reduction and minimal decision algorithm change or not when a new instance is added to the universe.
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