finite covering 中文意思是什麼
finite covering
解釋
有限覆蓋-
Every open covering of x has a finite sub-covering.
每個開覆蓋都有一個有限子覆蓋。 -
It is a main task of general topology to compare different spaces. mappings which connect different spaces are important tools to complete it. which mapping preserves some special generalized metric space is a basic probleme in investigating generalized metric spaces by mappings. g - first countable spaces and g - metri / able spaces have many important topological properities so to investigate which mapping preserves them is very necessary. in [ 7 ], clnian liu and mu - ming dai prove that open - closed mappings preserve g - metri / able spaces ; whether open mappings preserve g - first countable spaces is an open probleme asked by tanaka in [ 6 ]. in [ 4 ], sheng - xiang xia introduces weak opewn mappings and investigates the relations between them and 1 - sequence - covering mappings. in the second section of this article, we investigate weak open mappings have the relations with other mappings and prove that the finite - to - one weak open mappings preserve g - first countable, spaces and weak open closed mapping preserve g - metrizable spaces. in the third section, we investigate an example to show that perfect mappings do not preserve g - first countable spaces, g - metrizable spaces, sn - first countable spaces and sn - metrizable spaces
在文獻[ 4 ]中，夏省祥引進了弱開映射，並研究了它和1 -序列覆蓋映射的關系。本文在第二節研究了弱開映射與序列商映射，幾乎開映射的關系，證明了有限到一的弱開映射保持g -第一可數空間；弱開閉映射保持g -度量空間。第三節研究了文獻[ 5 ]中的一個例子，證明了完備映射不保持g -第一可數空間， g -度量空間， sn -第一可數空間， sn -度量空間。 -
X is quasi-compact(that is, every open covering of x has a finite sub-covering).
X是擬緊的（即對于X的每個開覆蓋都有一個有限子覆蓋）。 -
For a given finite connected graph f, a group h of automorphisms of f and a finite group a = z, du, kawk and xu ( see [ 6 ] ) get some new matrix - theoretical characterizations to classify all the connected regular coverings of f having a as its covering transformation group, on which each automorphism in h can be lifted
設為有限連通圖， h為它的自同構群的一個子群， a為給定一個初等交換p -群。杜少飛， kawk和徐明曜用矩陣的方法將的正則連通覆蓋圖進行了分類，其中以a作其為覆蓋變換群，並且h可提升。 -
X is quasi - compact ( that is, every open covering of x has a finite sub - covering )
X是擬緊的（即對于x的每個開覆蓋都有一個有限子覆蓋） 。 -
The notion of simple connectedness came from topology, and the corresponding ones also appear in some subjects such as analysis. it was given new meaning when introduced in the representation theory. there are close relations between the simple connectedness of finite - dimensional algebras and the covering theory
單連通的概念來源於拓撲學，此外在分析等學科中也有相應的概念，引入表示論中后又被賦予新的意義。
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