Results 31 to 40 of about 1,018,893 (229)

Topological spaces with the Freese--Nation property II [PDF]

, 2019
The aim of this paper is to study the class of spaces with the FNS property and $\pi-\FNS$ property. We shown that compact spaces with the FNS property for some base consisting of cozero-sets are openly generated spaces and spaces with the $\pi-\FNS ...
Bąk, Judyta, Kucharski, Andrzej
core   +2 more sources

Continuous functions on extremally disconnected spaces [PDF]

Transactions of the American Mathematical Society, 1995
Using results and techniques due to Abramovich, Arenson and Kitover it is shown that each fixed-point set of a selfmap of a compact extremally disconnected space is a retract of that space, and that the retraction can be constructed from the particular selfmap itself.
openaire   +2 more sources

Insertion of a measurable function [PDF]

, 1994
Some theorems on the existence of continuous real-valued functions on a topological space (for example, insertion, extension, and separation theorems) can be proved without involving uncountable unions of open sets.
Kotzé, W, Kubiak, T
core   +2 more sources

Measure-theoretic characterizations of hereditarily-normal spaces

International Journal of Mathematics and Mathematical Sciences, 1992
In this paper we characterize hereditarily-normal spaces in terms of the measure-theoretic properties of the lattice of closed sets. We then generalize from that lattice to other lattices. We apply the results to extremally-disconnected spaces.
Joseph Hertzlinger
doaj   +1 more source

Remainders of extremally disconnected spaces and related objects

Topology and its Applications, 2018
In this article, we study remainders of extremally disconnected spaces and extremally disconnected remainders. Extremally disconnected spaces satisfying certain homogeneity type conditions are at the center of it. It is established that the absolute X of
A. Arhangel'skii
semanticscholar   +1 more source

On Semicompact Sets and Associated Properties

International Journal of Mathematics and Mathematical Sciences, 2009
We continue the study of semicompact sets in a topological space. Several properties, mapping properties of semicompact sets are studied. A special interest to 𝑆𝐶𝑆 spaces is given, where a space 𝑋 is 𝑆𝐶𝑆 if every subset of 𝑋 which is semicompact in 𝑋 is
Mohammad S. Sarsak
doaj   +1 more source

On Generalized Closed Sets and Generalized Pre-Closed Sets in Neutrosophic Topological Spaces

Mathematics, 2018
In this paper, the concept of generalized neutrosophic pre-closed sets and generalized neutrosophic pre-open sets are introduced. We also study relations and various properties between the other existing neutrosophic open and closed sets. In addition, we
Wadei Al-Omeri, Saeid Jafari
doaj   +1 more source

Some new classes of topological spaces and annihilator ideals

, 2014
By a characterization of semiprime $SA$-rings by Birkenmeier, Ghirati and Taherifar in \cite[Theorem 4.4]{B}, and by the topological characterization of $C(X)$ as a Baer-ring by Stone and Nakano in \cite[Theorem 3.25]{KM}, it is easy to see that $C(X ...
Taherifar, A.
core   +1 more source

Countably I-Compact Spaces

International Journal of Mathematics and Mathematical Sciences, 2001
We introduce the class of countably I-compact spaces as a proper subclass of countably S-closed spaces. A topological space (X,T) is called countably I-compact if every countable cover of X by regular closed subsets contains a finite subfamily whose ...
Bassam Al-Nashef
doaj   +1 more source

On rings of real valued clopen continuous functions

Applied General Topology, 2018
Among variant kinds of strong continuity in the literature, the clopen continuity or cl-supercontinuity (i.e., inverse image of every open set is a union of clopen sets) is considered in this paper.
Susan Afrooz, Fariborz Azarpanah, Masoomeh Etebar   +2 more
doaj   +1 more source