A New Form of Fuzzy Compact Spaces and Related Topics via Fuzzy Idealization

Fuzzy ideals and the notion of fuzzy local function were introduced and studied by Sarkar[12] and by Mahmoud in [9]. The purpose of this paper deals with a fuzzy compactness modulo a fuzzy ideal. Many new sorts of weak and strong fuzzy compactness have been introduced to fuzzy topological spaces in the last twenty years but not have been studied using fuzzy ideals so,the main aim of our work in this paper is to define and study some new various types of fuzzy compactness with respect to fuzzy ideals namely fuzzy L-compact and L*-compact spaces. Also fuzzy compactness with respect to ideal is useful as unification and generalization of several others widely studied concepts. Possible application to superstrings and E∞ space-time are touched upon.     

On the order conditions of fuzzy convergence classes

By means of the order structure of the related lattice, the LIMINF condition of fuzzy convergence classes is proposed in this paper, which reflects the essential difference between fuzzy convergence classes and ordinary convergence classes. The relationship between the LIMINF condition and two related conditions proposed by Liu and Wang respectively are discussed. The theory of fuzzy convergence classes based on LIMINF condition is established for topological molecular lattices, L-topological spaces (in the sense of Chang or Lowen), weakly induced spaces, and induced spaces.     

Probabilistic metrization of fuzzy uniformities

Modifying the structure of fuzzy uniform spaces introduced by Lowen [5] we propose a further concept of fuzzy uniformities—so-called fuzzy T-     

Probabilistische Topologien

Referring only to closed L-fuzzy sets we introduce a concept of probabilistic topological spaces including random metric spaces ([17]) statistical metric spaces ([9][15]) and fuzzy uniform spaces studied by Lowen [11]. In particular probabilistic topologies in the sense of Frank [5] satisfying the additional property (R3) are equivalent to systems of closed [0, 1]-fuzzy sets. Moreover random topologies as well as fuzzy topologies ([3],[13]) equipped with the property (03) can be considered as probabilistic topologies.     

Almost compactness in fuzzy topological spaces

We introduce and study almost compactness for fuzzy topological spaces. We show that the almost continuous image of an almost compact fuzzy topological space is almost compact. Moreover, we show that generally almost compactness for fuzzy topological spaces is not product-invariant, but if X and Y are almost fuzzy topological spaces and X is product related to Y, then their fuzzy topological product is almost compact.     

L-拓扑空间的弱局部强F紧性及单点强F紧化

以R.Lowen的强F紧性为基础,定义了L-拓扑空间的弱局部强F紧性及单点强F紧化,推广了有关弱局部紧拓扑空间和拓扑空间的单点紧化的若干结果,证明了L-拓扑空间的弱局部强F紧性是拓扑空间的弱局部紧性的L-推广。     

L—Fuzzy拓扑空间的正则

本文给出一种在Ｌ－Ｆｕｚｚｙ拓扑空间中的正则，记作Ｎ－正则，且证明了它不仅强于文献「１」中所提出的正则，而且还具有一系列好的性质，最后我们给出一个定理说明了Ｎ－正则与良紧性之间的关系。     

A Kuratowski–Mrówka theorem in approach theory

In this paper we give a number of arguments why, in approach theory, the notion of compactness which from the intrinsic categorical point of view seems most satisfying is 0-compactness, i.e., measure of compactness equal to zero. It was already known from [R. Lowen, Kuratowski's measure of noncompactness revisited, Quart. J. Math. Oxford 39 (1988) 235–254] that measure of compactness has good properties and good interpretations for both topological and metric approach spaces. Here, introducing notions of closed and proper mappings in approach theory, which satisfy all the intrinsic categorical axioms put forth in [Clementino et al., A functional approach to topology, in: M.C. Pedicchio, W. Tholen (Eds.) Categorical Foundations Special Topics in Order, Topology, Algebra, and Sheaf Theory, Cambridge University Press, 2003], we prove fundamental results concerning these concepts, also linked to 0-compactness, and we give a Kuratowski–Mrówka-type characterization of 0-compactness.     

Asymmetry and bicompletion of approach spaces

We develop a bicompletion theory for the category Ap₀ of T₀ approach spaces in the sense of Lowen [R. Lowen, Approach Spaces: The Missing Link in the Topology-Uniformity-Metric Triad, Oxford University Press, Oxford, 1997], which extends the completion theory obtained in [R. Lowen, K. Robeys., Completions of products of metric spaces, Quart. J. Math. Oxford 43 (1991) 319-338] for the subcategory of Hausdorff uniform approach spaces. Moreover, we prove it to be firmly epireflective (in the sense of [G.C.L. Brümmer, E. Giuli, A categorical concept of completion of objects, Comment. Math. Univ. Carolin. 33 (1992) 131-147]) with respect to a certain morphism class of dense embeddings.     

FUZZY PRETOPOLOGICAL SPACES, AN EXTENSIONAL TOPOLOGICAL EXTENSION OF FTS

O.Introduction'ByacrazytopologyonasetXwemeanasubsetofixwhichisclosedunderfiniteintersections,arbitraryulilonsandcolltainsalltheconstantfuZzysets.ItiswellknownthatthecategoryFTSoffuzzytopologicalspacesisawell--fibredtopologicalconstruct,andsinceitcoDtainsthecategoryTopasabothreflectiveandcoreflectivesubcategory)likeTOP,thiscategorylacksmanyconvenientpropertiessuchasextensionality(fordefinitionsee[6]or4.1inthispaper),cartesianclosednessandbeingatopologicaluniverse(see[1,6]fordefinitons).SoH…     

Compactness properties in the fuzzy real line

It is the purpose of this paper to give the solution to a number of open questions in [14], concerning the compactness properties of the fuzzy real line and the fuzzy real unit interval.However using the model of the fuzzy real line which we already proposed in [9, 12] we are able to describe all compactness properties not only of the spaces mentioned above but actually of several large classes of subspaces of the fuzzy real line; and thus the answers to the questions in [14] follow as easy consequences of our general results.     

Compact Hausdorff fuzzy topological spaces are topological

Many examples of compact fuzzy topological spaces which are highly non topological are known [5, 6]. Equally many examples of Hausdorff fuzzy topological spaces which are highly non topological can be given. In this paper we show that the two properties - compact and Hausdorff - combined however necessarily imply that the fuzzy topological space is topological. This at once solves some open questions with regard to the compactification of fuzzy topological spaces [8]. It also emphasizes once more the particular role played by compact Hausdorff topological spaces not only in the category of topological spaces but even in the category of fuzzy topological spaces.     

LOCAL COMPACTNESS IN SEMI-UNIFORM CONVERGENCE SPACES

Abstract

Local compactness is studied in the highly convenient setting of semi-uniform convergence spaces which form a common generalization of (symmetric) limit spaces (and thus of symmetric topological spaces) as well as of uniform limit spaces (and thus of uniform spaces). It turns out that it leads to a cartesian closed topological category and, in contrast to the situation for topological spaces, the local compact spaces are exactly the compactly generated spaces. Furthermore, a one-point Hausdorff compactification for noncompact locally compact Hausdorff convergence spaces is considered.¹     

Representation and duality for Hilbert algebras

In this paper we introduce a special kind of ordered topological spaces, called Hilbert spaces. We prove that the category of Hilbert algebras with semi-homomorphisms is dually equivalent to the category of Hilbert spaces with certain relations. We restrict this result to give a duality for the category of Hilbert algebras with homomorphisms. We apply these results to prove that the lattice of the deductive systems of a Hilbert algebra and the lattice of open subsets of its dual Hilbert space, are isomorphic. We explore how this duality is related to the duality given in [6] for finite Hilbert algebras, and with the topological duality developed in [7] for Tarski algebras.      

Fuzzy Soft Topological Groups

Notions of Lowen type fuzzy soft topological space are introduced and some of their properties are established in the present paper. Besides this, a combined structure of a fuzzy soft topological space and a fuzzy soft group, which is termed here as fuzzy soft topological group is introduced. Homomorphic images and preimages are also examined. Finally, some definitions and results on fuzzy soft set are studied.     

F连续线性映象空间

本文采用（１）中给出的Ｆｕｚｚｙ拓扑线性空间的定义，并利用Ｆｕｚｚｙ拓扑线性空间的有关理论，对Ｆｕｚｚｙ连续线性映象空间作了较深入的研究。     

L—Fuzzy拓扑空间中的可数SR—紧性

从层次结构入手引入L－fuzzy拓扑空间中的可数SR－紧性,证明了可数SR－紧性对强半闭子集遗传,可数SR－紧子集在S－不定映射 像保持,给出了可数SR－紧性的几何刻画与有限交性质的刻画。     

The stone-čech compactification in the category of fuzzy topological spaces

In this paper we obtain a reflective subcategory C of the category FTS of fuzzy topological spaces. The associated reflection $\text{β}$ has properties similar to those of the ‘Stone-?ech’ compactification β and, in effect, is an extension of it. We study relations between β and $\text{β}$ in particular subcategories of FTS; $\text{β}$ is completely determined in the case of fuzzy topological spaces topologically generated.     

Convex compactness and its applications

The concept of convex compactness, weaker than the classical notion of compactness, is introduced and discussed. It is shown that a large class of convex subsets of topological vector spaces shares this property and that is can be used in lieu of compactness in a variety of cases. Specifically, we establish convex compactness for certain familiar classes of subsets of the set of positive random variables under the topology induced by convergence in probability. Two applications in infinite-dimensional optimization—attainment of infima and a version of the Minimax theorem—are given. Moreover, a new fixed-point theorem of the Knaster-Kuratowski-Mazurkiewicz-type is derived and used to prove a general version of the Walrasian excess-demand theorem.     

On Some L-extensions of Dimensions of Topological Spaces

The concepts of covering dimension,small inductive dimension and large inductive dimension for topological spaces are extended to L-topological spaces using the quasi-coincidence relation.Besides getting some characterizations,it is also seen that all these characterizations are good in the sense of Lowen.