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 共查询到18条相似文献,搜索用时 46 毫秒
1.
利用Locale中的完全正则元和零维元构造性地给出了任意Locale的完全正则反射以及零维反射的描述,并且对于满足‘(?)’关系插入性的Locale,特别地,对正规Locale,证明了全体正则元构成的Locale是其正则反射.进而,利用平稳(flat)子Locale的扩张引理给出了Locale的紧完全正则反射,紧零维反射以及紧正则反射的构造性描述.  相似文献   

2.
Locale范畴中的零维性   总被引:1,自引:0,他引:1  
贺伟  罗懋康 《数学学报》1998,41(3):539-544
本文讨论locale的零维性质,主要结果有:(1)给出localeA的核映射(nucleus)构成的localeN(A)中上确界的点式刻划,并得到了N(A)的紧性与A的紧性之间的关系;(2)给出零维locale与coherentlocale之间的关系,以及零维locale的紧零维反射;(3)给出零维locale范畴在locale范畴中的刻划.  相似文献   

3.
本文研究locale范畴的反射子范畴,给出反射子范畴的刻划定理,从一般的locale出发,完全构造性地给出了locale的正则反射、完全正则反射和零维反射的构造.  相似文献   

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贺伟  罗懋康 《中国科学A辑》2006,36(7):757-763
1972年, Isbell利用locale中由正规覆盖构成的一致结构的完备化, 证明了仿紧完全正则locale范畴是locale范畴的满反射子范畴. 本文通过在locale的补零元理想格上做核映射的方法, 给出locale的仿紧完全正则反射的明确构造, 并证明locale的仿紧完全正则反射是locale的 Stone-Čech紧化的子locale.  相似文献   

6.
一致Locale的乘积   总被引:1,自引:0,他引:1  
梁基华 《数学学报》1998,41(2):411-041
本文利用Locale上的收敛结构研究一致Locale的乘积结构,证明了一致Lo cale的完备性关于Locale积和弱积封闭.  相似文献   

7.
Locale的正则紧反射   总被引:1,自引:0,他引:1  
贺伟 《数学学报》1999,42(3):441-444
locale的正则紧反射函子的构造的明确描述问题是由BanaschewskiB.和MulveyC.J.于1980年提出的,十多年来一直没有进展。本文通过在locale上引入一种二元关系,给出了locale的正则紧反射函子的构造性描述。  相似文献   

8.
构造性地定义了Locale间的Isbell,紧开及点态函数空间,研究了其良好的范畴性质(Proper和Admissible性质)及分离性质.重新得到了有指数Locale的结构.这些工作是寻找Locale范畴中的方便范畴的基础。  相似文献   

9.
李永明 《数学年刊A辑》2003,24(6):695-704
构造性地定义了Locale间的Isbell,紧开及点态函数空间,研究了其良好的范畴性质(Proper和Admissible性质)及分离性质.重新得到了有指数Locale的结构.这些工作是寻找Locale范畴中的方便范畴的基础.  相似文献   

10.
这篇注记证明判断一个图是否有3-正则子图的问题,即使对于节点次不超过4的平面力,仍然是NP-完全的,而且,此结果是最好的可能。  相似文献   

11.
We study isocompactness in Loc defined, exactly as in Top, by requiring that every countably compact closed sublocale be compact. This is a genuine extension of the same-named topological concept since every Boolean (or, even more emphatically, every paracompact) locale is isocompact. A slightly stronger variant is defined by decreeing that the closure of every complemented countably compact sublocale be compact. Dropping the adjective “complemented” yields a formally even stronger property, which we show to be preserved by finite products. Metrizable locales (or, more generally, perfectly normal locales) do not distinguish between the three variants of isocompactness. Each of the stronger variants of isocompactness travels across a proper map of locales, and in the opposite direction if the map is a surjection in Loc.  相似文献   

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本文证明了在正规locale范畴中,Banaschewski-Mulvey形式的紧正则反射与Johnstone形式的Wallman紧化一致,从而推广了Johnstone在文献[4]中的主要结果.  相似文献   

14.
We consider regular epimorphisms in the category Loc of locales. Closed surjections with subfit domain are regular epimorphisms. However, there exists a closed surjection which is the composite of two regular epimorphisms without being regular epic itself. This example answers both of the following questions in the negative: Y. Li"s question of whether weak quotient maps are necessarily regular epimorphisms, and P. Johnstone"s related question of whether regular epimorphisms compose. It follows that not all extremal epimorphisms in Loc are regular. The weak quotient maps of Y. Li and the equationally closed subframes of A. Pultr and A. Tozzi are shown to be dual notions. We also give a new characterization of regular epimorphisms in Loc.  相似文献   

15.
Locale上的收敛结构   总被引:3,自引:1,他引:3  
梁基华 《数学学报》1995,38(3):294-300
本文从点式处理角度,在Locale上成功地建立了收敛结构。利用它研究了一致Locale的完备性、刻划紧性,、界定了Locale上一种满意的Hausdorff分离性,  相似文献   

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Let X and Y be completely regular locales. We show that the properness of a localic map f: X → Y can be characterized in terms of extension between compactifications.  相似文献   

18.
A map f:XY between Hausdorff topological spaces is k-continuous if its restriction f| K to every compact subspace K of X is continuous. X is called a k R -space if every k-continuous function from X to a Tychonoff space is continuous. In this paper we investigate the category of Tychonoff k R -spaces, and show that it is Cartesian closed (thus convenient in the sense of Wyler).  相似文献   

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