• 2022-10-30
    设集合A={1,2,3,4,5}上偏序关系的哈斯图为, 则子集B={2,3,4}的最大元;最小元;极大元;极小元;上界;上确界;下界;下确界。https://edu-image.nosdn.127.net/00118AE5B898CF17121A032D76DC609F.png?imageView&thumbnail=890x0&quality=100