半极小集及其应用

在完备格中,引入半极小集概念,得到完备格L是半连续格当且仅当每一个元都有半极小集这一结论,同时给出半极小集的一些刻画性质.在半Scott连续映射的帮助下,给出了保半极小集的一些映射性质,并用这些性质证明了半连续格的子半格、商半格还是半连续格.     

半连续格上的半Scott拓扑与半Lawson拓扑

在完备格上引入了半Scott拓扑与半Lawson拓扑,讨论了半连续格和强连续格上半Scott拓扑与半Lawson拓扑的一些基本性质。     

半连续格的半素极小集与序同态扩张

对完备格引入半素极小集的概念,证明完备格L为半连续格当且仅当L中的每个元在L中存在半素极小集,给出半连续格的两个序同态扩张定理.     

相容半连续格上的相容半基及局部相容半基

作为半连续格上半基和局部半基的推广,文章引入相容半连续格的相容半基及局部相容半基的概念。讨论了它们的基本性质,特别地,借助于相容半基与局部相容半基给出了相容半连续格的一些等价刻画。     

有可数基的半一致格

在[1]中,Carlson 用接近结构刻划了可展空间,基本的结果是:一个拓扑空间 E是可展的当且仅当它的拓扑由一个有可数基的半一致(即接近)导出。本文建立有可数基的半一致格的几个结果,它们可看作是度量空间的相应定理的推广。这些结果将特别适用于可展拓扑空间与模糊半一致空间。     

广义半Smooth格

引入了广义半Smooth格和广义半Smooth代数格的概念,讨论了它们的一些基本性质,证明了完备格L是广义完全分配格当且仅当L是拟连续的广义半Smooth格。     

完全分配格与点格

本文第一部分利用完备格上的上拓扑子基,给出完全分配格与点格的若干新刻划,并讨论其上的 Scott 拓扑与 Lawson 拓扑的基与子基的构造.第二部分讨论点格与代数格的关系,证明了 L 是点格当且仅当 L 为代数格且 L~(op)为完全 Heyting代数,并证明了代数偏序集范畴与点格范畴是等价的.     

坡代数上半模的基

有单位元的坡是加法幂等半环,在加法诱导的偏序下乘积小于等于每个因子。布尔代数、极大-极小模糊代数和任意分配格均是坡的特例。本文研究坡上半模的基。对于坡上的半模,标准基和基的基数一般都不是唯一的。我们引入既约基的概念并给出它的特征。既约基如果存在,则是唯一的。讨论了标准基和既约基之间的关系。     

拓扑分子格中的半正则半开元和正则半开元

本文引入并研究了拓扑分子格中的半正则半开（半正则半闭）元和正则半开（正则半闭）元的概念。在此基础上，引入了几乎不定（几乎不定开、几乎不定闭）、几乎半连续（几乎半开、几乎半闭）和几乎半不定（几乎半不定开、几乎半不定闭）序同态的概念，同时给出了它们的若干特征性质，以及它们同其它序同态之间的关系。     

半局部环的一个特征

给出了可换半局部环的一个外部特征，证明了Ｒ为半局部环当且仅当存在可逆Ｒ－模，其Ｔｏｐ为Ａｒｔｉｎ模．     

Z-半连续格

作为连续格和半连续格的公共推广,引入了广义理想子系统Z、Z-半连续格及强Z-连续格的概念,讨论了它们的基本性质和Z-半连续格的函数空间的结构,给出了强Z-连续格到方体的嵌入,证明了当子系统Z满足一定条件时,Z-半连续格范畴SCLZ是笛卡儿闭的。     

拟半连续格和交半连续格

作为半连续格的推广, 引入了拟半连续格的概念. 讨论了拟半连续格的基本性质. 在拟半连续格上得到了类似于拟连续偏序集的一些主要结果. 同时探讨了半连续格、拟半连续格、交半连续格、交连续格、强连续格几种不同结构之间的关系. 最后,讨论了半连续函数空间仍是半连续格的条件.     

GENERALIZATIONS AND CARTESIAN CLOSED SUBCATEGORIES OF SEMICONTINUOUS LATTICES

In this article, the authors mainly study how to obtain new semicontinuous lattices from the given semicontinuous lattices and discuss the conditions under which the image of a semicontinuous projection operator is also semicontinuous. Moreover, the authors investigate the relation between semicontinuous lattices and completely distributive lattices. Finally, it is proved that the strongly semicontinuous lattice category is a Cartesian closed category.     

A structure theorem for dismantlable lattices and enumeration

The concept of `adjunct' operation of two lattices with respect to a pair of elements is introduced. A structure theorem namely, `A finite lattice is dismantlable if and only if it is an adjunct of chains' is obtained. Further it is established that for any adjunct representation of a dismantlable lattice the number of chains as well as the number of times a pair of elements occurs remains the same. If a dismantlable lattice L has n elements and n+k edges then it is proved that the number of irreducible elements of L lies between n-2k-2 and n-2. These results are used to enumerate the class of lattices with exactly two reducible elements, the class of lattices with n elements and upto n+1 edges, and their subclasses of distributive lattices and modular lattices. This revised version was published online in June 2006 with corrections to the Cover Date.     

Crosscut-Simplicial Lattices

We call a finite lattice crosscut-simplicial if the crosscut complex of every nuclear interval is equal to the boundary of a simplex. Every interval of such a lattice is either contractible or homotopy equivalent to a sphere. Recently, Hersh and Mészáros introduced SB-labelings and proved that if a lattice has an SB-labeling then it is crosscut-simplicial. Some known examples of lattices with a natural SB-labeling include the join-distributive lattices, the weak order of a Coxeter group, and the Tamari lattice. Generalizing these three examples, we prove that every meet-semidistributive lattice is crosscut-simplicial, though we do not know whether all such lattices admit an SB-labeling. While not every crosscut-simplicial lattice is meet-semidistributive, we prove that these properties are equivalent for chamber posets of real hyperplane arrangements.     

Lattices with large minimal extensions

This paper characterizes those finite lattices which are a maximal sublattice of an infinite lattice. There are 145 minimal lattices with this property, and a finite lattice has an infinite minimal extension if and only if it contains one of these 145 as a sublattice. Received October 5, 1998; accepted in final form May 19, 1999.     

开广义序同态的刻划及拓扑分子格的特征与权

王国俊先生于〔１〕中借助闭元成功地引入了开广义序同态的概念。本文给出了开广义序同态的一个刻划并对其是否增加拓扑分子格的权与特征等问题进行了研究，得到了积拓扑分子格的特征与权与因子拓扑分子格的特征与权间的关系，从而部分回答了ＬＦ拓扑中关于特征的两个公开问题。     

(∈,∈∨q)-模糊软格

将模糊软集的概念与格相结合,引入了(∈,∈∨q)-模糊软格和(∈,∈∨q)-模糊软格的(∈,∈∨q)-模糊软子格的概念,给出了它们的若干代数性质.定义了格的模糊软同态概念,证明了(∈,∈∨q)-模糊软格在格的一个模糊软同态下的像与原像仍为(∈,∈∨q)-模糊软格的结论.