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参考答案:
![](https://cos-cdn.shuashuati.com/shuashuati-web/2024-0521-0905-00/logo-new-ad743.png)
【填空题】设A={{1},{2},{4},{1,2},{1,4},{2,4},{3,4},{1,3,4},{2,3,4}},A上的偏序关系R={<x,y>|x∈A^y∈A^x⊆y},B={{2},{4}},则在偏序集<A,R>中B的所有上界为(),所有下界为()
【填空题】设A={{1},{2},{4},{1,2},{1,4},{2,4},{3,4},{1,3,4},{2,3,4}},A上的偏序关系R={<x,y>|x∈A^y∈A^x⊆y},B={{2},{4}},则在偏序集<A,R>中B的所有上界为(),所有下界为()
参考解析:
![](https://cos-cdn.shuashuati.com/shuashuati-web/2024-0521-0905-00/logo-new-ad743.png)