紧性为点集拓扑中的基本概念，若X的任一开覆盖有有限子覆盖，称拓扑空间X的子集K为紧集，若能从X的任一覆盖K的开集族中取有限覆盖。
讨论了近似良紧性与良紧性之间的关系。
The relationships between the nearly nice compactness and the nice compactness are discussed.
证明了GO-空间子空间的正交紧性和弱子正交紧性是等价的。
We proved orthocompactness and weakly suborthocompactness are equivalent for all subspaces of product of two GO-space.
本文讨论了赋予局部有限拓扑的非空闲子集超空间的局部紧性。
In this paper the local compactness of the nonempty closed subsets hyperspaces with locally finite topology is discussed.
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