Results 21 to 30 of about 71 (71)

More on μ-semi-Lindelöf sets in μ-spaces

Demonstratio Mathematica, 2021
Sarsak [On μ\mu -compact sets in μ\mu -spaces, Questions Answers Gen. Topology 31 (2013), no. 1, 49–57] introduced and studied the class of μ\mu -Lindelöf sets in μ\mu -spaces. Mustafa [μ\mu -semi compactness and
Sarsak Mohammad S.
doaj   +1 more source

rc‐continuous functions and functions with rc‐strongly closed graph

International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 72, Page 4547-4555, 2003., 2003
The family of regular closed subsets of a topological space is used to introduce two concepts concerning a function f from a space X to a space Y. The first of them is the notion of f being rc‐continuous. One of the established results states that a space Y is extremally disconnected if and only if each continuous function from a space X to Y is rc ...
Bassam Al-Nashef
wiley   +1 more source

Some properties of maximal open sets

International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 21, Page 1331-1340, 2003., 2003
Some fundamental properties of maximal open sets are obtained, such as decomposition theorem for a maximal open set. Basic properties of intersections of maximal open sets are established, such as the law of radical closure.
Fumie Nakaoka, Nobuyuki Oda
wiley   +1 more source

Semi‐precontinuous functions and properties of generalized semi‐preclosed sets in topological spaces

International Journal of Mathematics and Mathematical Sciences, Volume 29, Issue 2, Page 85-98, 2002., 2002
Andrijević (1986) introduced the class of semi‐preopen sets in topological spaces. Since then many authors including Andrijević have studied this class of sets by defining their neighborhoods, separation axioms and functions. The purpose of this paper is to provide the new characterizations of semi‐preopen and semi‐preclosed sets by defining the ...
G. B. Navalagi
wiley   +1 more source

Neighborhood spaces

International Journal of Mathematics and Mathematical Sciences, Volume 32, Issue 7, Page 387-399, 2002., 2002
Neighborhood spaces, pretopological spaces, and closure spaces are topological space generalizations which can be characterized by means of their associated interior (or closure) operators. The category NBD of neighborhood spaces and continuous maps contains PRTOP as a bicoreflective subcategory and CLS as a bireflective subcategory, whereas TOP is ...
D. C. Kent, Won Keun Min
wiley   +1 more source

κ-strong sequences and the existence of generalized independent families

Open Mathematics, 2017
In this paper we will show some relations between generalized versions of strong sequences introduced by Efimov in 1965 and independent families. We also show some inequalities between cardinal invariants associated with these both notions.
Jureczko Joanna
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More On Weak Soft Axioms

Moroccan Journal of Pure and Applied Analysis, 2020
In this paper, we continue studying the properties of weak soft axioms discussed and studied in [8]. We initiate and explore soft semi-R0 spaces at soft point in terms of soft semi-open sets and study its characterizations and properties.
Hussain Sabir
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Quantification of topological concepts using ideals

International Journal of Mathematics and Mathematical Sciences, Volume 26, Issue 9, Page 561-579, 2001., 2001
We introduce certain ideals of real‐valued functions as a natural generalization of filters. We show that these ideals establish a canonical framework for the quantification of topological concepts, such as closedness, adherence, and compactness, in the setting of approach spaces.
Robert Lowen, Bart Windels
wiley   +1 more source

Some applications of minimal open sets

International Journal of Mathematics and Mathematical Sciences, Volume 27, Issue 8, Page 471-476, 2001., 2001
We characterize minimal open sets in topological spaces. We show that any nonempty subset of a minimal open set is pre‐open. As an application of a theory of minimal open sets, we obtain a sufficient condition for a locally finite space to be a pre‐Hausdorff space.
Fumie Nakaoka, Nobuyuki Oda
wiley   +1 more source

On generalizations of regular‐Lindelöf spaces

International Journal of Mathematics and Mathematical Sciences, Volume 27, Issue 9, Page 535-539, 2001., 2001
We study nearly regular‐Lindelöf, almost regular‐Lindelöf and weakly regular‐Lindelöf spaces. Characterizations and some properties for these spaces are proposed. Relations among them are also studied.
Anwar Jabor Fawakhreh, Adem Kiliçman
wiley   +1 more source