关于基于正规子群的上下近似的注记  

A Note on the Upper and Lower Approximations Based on the Normal Subgroup

作　　者：祝令江[1] 王莉[1] 王开宝[1] 姚炳学[1] 

机构地区：[1]聊城大学数学与科学学院

出　　处：《聊城大学学报（自然科学版）》2008年第3期5-7,共3页Journal of Liaocheng University:Natural Science Edition

基　　金：教育部科技研究重点项目资助(206089)

摘　　要：指出文献[1]中性质2.4,2.5是错误的,性质3.5,3.6,3.7条件消弱但结论不变;给出群中同余的几个结论,并给出证明;给出二重近似的概念及一些性质.That the positions 2.4,2. 5 are wrong is pointed out; and the conditions of positions of 3. 5,3. 6,3. 7 are reduced,but the conclusions are invariable;same conclusions about congruence in a group are gave out;the concept of double approximation is gave out and same positions are pointed out.

关 键 词：粗糙子群 粗糙正规子群 二重近似 

分 类 号：O159[理学—数学]