L─Fuzzy拓扑空间的局部连通性

文［１］曾在广义拓扑分子格中提出了一种连通性。本文在Ｌ—ｆｕｚｚｙ拓扑空间中给出了这种连通性的几种刻划，并引入了Ｌ—ｆｙｚｚｙ拓扑空间的局部连通性。这种局部连通性是有限可乘的，商序同态保持的且是好的推广。另外，ｆｕｚｚｙ实直线是局部连通的。     

On (co)homology locally connected spaces

We prove that there exists a cohomology locally connected compact metrizable space which is not homology locally connected. In the category of compact Hausdorff spaces a similar result was proved earlier by G.E. Bredon.     

Uniformly locally connected uniform <Emphasis Type="Italic">σ</Emphasis>-frames

We introduce and study the concept of a uniformly locally connected uniform σ-frame. The uniformly locally connected reflection of a locally connected uniform σ-frame is constructed.      

An example of a nonarcwise connected rim-countable locally connected continuum

An example of a rim-countable, locally connected, but nonarcwise connected continuum is constructed, which is important for the classification of locally connected continua. The point of interest in this result is that there are no metrizable locally connected continua with the above properties. Translated fromMatematicheskie Zametki, Vol. 65, No. 5, pp. 659–666, May, 1999.     

Conditions under which the least compactification of a regular continuous frame is perfect

We characterize those regular continuous frames for which the least compactification is a perfect compactification. Perfect compactifications are those compactifications of frames for which the right adjoint of the compactification map preserves disjoint binary joins. Essential to our characterization is the construction of the frame analog of the two-point compactification of a locally compact Hausdorff space, and the concept of remainder in a frame compactification. Indeed, one of the characterizations is that the remainder of the regular continuous frame in each of its compactifications is compact and connected.     

Some notes on connectedness in nearness frames

Abstract

We study the uniform connection properties of uniform local connectedness, a weaker variant of the latter, and a certain property S in the context of nearness frames. We show that the uniformly locally connected nearness frames form a reflective subcategory of the category of nearness frames whose underlying frame is locally connected. Amongst other results we show that these uniform connection properties are conserved and reflected by perfect nearness extensions which are uniformly regular.     

Connectedness in Metric Frames

A new metric diameter for a locally connected metric frame is constructed which is finer than the original one. Amongst other results, this construction allows a proof that the category of uniformly locally connected metric frames and uniform frame maps is reflective in the category of locally connected metric frames and uniform frame maps. Mathematics Subject Classification (2000) 54A05.     

Quantah的连通性

The concepts of connectedness and locally connectedness is introduced for right-side idempotent quantales. Some properties of connected quantale are studied, and then the equivalent characterization of connected quantale is also given.     

On free spectra of finite completely regular semigroups and monoids

We show that a finite completely regular semigroup has a sub-log-exponential free spectrum if and only if it is locally orthodox and has nilpotent subgroups. As a corollary, it follows that the Seif Conjecture holds true for completely regular monoids. In the process, we derive solutions of word problems of free objects in a sequence of varieties of locally orthodox completely regular semigroups from solutions of word problems in relatively free bands.     

局部左正则纯正密群的一个等式

本文给出局部左正则纯正密群的一个等式.证明了一个完全正则半群是左半正规密群当且仅当它是局部左正则纯正密群.     

Completely regular ordered spaces

We present an example of a completely regular ordered space that is not strictly completely regular ordered. Furthermore, we note that a completely regular ordered I-space is strictly completely regular ordered provided that it satisfies at least one of the following three conditions: It is locally compact, it is a C-space, it is a topological lattice.     

On countable connected locally connected almost regular Urysohn spaces

We construct connected, locally connected, almost regular, countable, Urysohn spaces. This answers a problem of G.X. Ritter. We show that there are 2^c such non-homeomorphic spaces. We also show that there are 2^c non-homeomorphic spaces which are further rigid. We discuss the group of homeomorphisms of such spaces.The following question was raised by G.X. Ritter: Does there exist a countable connected locally connected Urysohn space which is almost regular? We answer this question in the affirmative and in fact, show that not only are there as many as 2^c such spaces but that there are just as many rigid spaces with the same properties. Furthermore we show that every countable Urysohn space is a subspace of such a space. We also prove that every countable group is isomorphic to the group of autohomeomorphisms of some connected locally connected almost regular Urysohn space. Examples are given of groups of order c which can be represented in this manner.     

Yet another patch construction for continuous frames and connections to the Fell compactification

It has been shown that the category of stably locally continuous frames and perfect frame homomorphisms reflects into the subcategory of continuous regular frames. The reflection functor is the patch frame construction, which has the following properties: For any stably locally continuous frame L and any regular frame M, a perfect frame homomorphism L → M factors uniquely through the patch frame of L. Furthermore, the patch is the universal solution to the problem of transforming the way–below relation into the well–inside relation. In this paper, we extend these results to the larger class of continuous frames, retaining functoriality and the universal properties, but at the price of sacrificing the reflection. We show that our patch construction can be obtained as a pushout involving the Fell compactification.     

A spread extension associated with Madden-type generators

Summary A frame homomorphism <InlineEquation ID=IE"3"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"4"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"5"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"6"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"7"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"8"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"9"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"10"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"11"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"12"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"13"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"14"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"15"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"16"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"17"><EquationSource Format="TEX"><![CDATA[$]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>f\: L\to M$ between locally connected frames is called a \emph{localic spread} if $\bigcup\limits_{u\in L}S_{u}$ is a basis for $M$, where <InlineEquation ID=IE"1"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"2"><EquationSource Format="TEX"><![CDATA[$$]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation> S_{u}=\{x\in M\mid x\Leqq_{c}f(u)\} $$ for each $u\in L$, where $x\Leqq_{c}h(u)$ denotes that ``$x$ is a component of $h(u)$'. Madden-type generators and relations are applied on $L$ to form a freely generated frame $CM$ induced by $j\: M\to CM$ leading to a \emph{spread extension} $j\circ f\: L\to CM$ of~$f$. In this article, we discuss properties of a local spread extension (which is not complete) between locally connected frames.     

On the resolvability of locally connected spaces

We solve a problem of Padmavally about resolvability of locally connected spaces, in the case where the space under consideration is regular.

     

On Locally Primitive Graphs of Order 18p

The authors investigate locally primitive bipartite regular connected graphs of order $18p$. It is shown that such a graph is either arc-transitive or isomorphic to one of the Gray graph and the Tutte $12$-cage.     

Connectedness extended to <Emphasis Type="Italic">σ</Emphasis>-frames

We introduce and study the concepts of connectedness and local connectedness in σ-frames. We also consider the local connectedness of the Stone-Čech compactification of a regular σ-frame.      

Hamiltonian properties of locally connected graphs with bounded vertex degree

We consider the existence of Hamiltonian cycles for the locally connected graphs with a bounded vertex degree. For a graph G, let Δ(G) and δ(G) denote the maximum and minimum vertex degrees, respectively. We explicitly describe all connected, locally connected graphs with Δ(G)?4. We show that every connected, locally connected graph with Δ(G)=5 and δ(G)?3 is fully cycle extendable which extends the results of Kikust [P.B. Kikust, The existence of the Hamiltonian circuit in a regular graph of degree 5, Latvian Math. Annual 16 (1975) 33-38] and Hendry [G.R.T. Hendry, A strengthening of Kikust’s theorem, J. Graph Theory 13 (1989) 257-260] on full cycle extendability of the connected, locally connected graphs with the maximum vertex degree bounded by 5. Furthermore, we prove that problem Hamilton Cycle for the locally connected graphs with Δ(G)?7 is NP-complete.     

Locally Completely Regular Epigroups

The object of the article is to characterize epigroups which are locally completely regular. Some subclasses of such epigroups are also described.