Results 21 to 30 of about 60 (60)
Perfect maps in compact (countably compact) spaces
International Journal of Mathematics and Mathematical Sciences, Volume 18, Issue 4, Page 773-776, 1995., 1993 In this paper, among other results, characterizations of perfect maps in compact Hausdorff(Fréchet, countably compact, Hausdorff) spaces are obtained.
G. L. Garg, Asha Goel
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Measures of Lindelof and separability in approach spaces
International Journal of Mathematics and Mathematical Sciences, Volume 17, Issue 3, Page 597-606, 1994., 1993 In this paper we introduce the notions of separability and Lindelöf in approach spaces and investigate their behaviour under products and subspaces.
R. Baekeland, R. Lowen
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International Journal of Mathematics and Mathematical Sciences, Volume 17, Issue 4, Page 687-692, 1994., 1994 In this paper we study θ‐regularity and its relations to other topological properties. We show that the concepts of θ‐regularity (Janković, 1985) and point paracompactness (Boyte, 1973) coincide. Regular, strongly locally compact or paracompact spaces are θ‐regular.
Martin M. Kovár
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On weaker forms of compactness Lindelöfness and countable compactness
International Journal of Mathematics and Mathematical Sciences, Volume 13, Issue 1, Page 55-59, 1990., 1988 A theory of e‐countable compactness and e‐Lindelöfness which are weaker than the concepts of countable compactness and Lindelöfness respectively is developed. Amongst other results we show that an e‐countably compact space is pseudocompact, and an example of a space which is pseudocompact but not e‐countably compact with respect to any dense set is ...
D. Baboolal, J. Backhouse, R. G. Ori
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Selections, Paracompactness and Compactness [PDF]
, 2010 2000 Mathematics Subject Classification: 54C60, 54C65, 54D20, 54D30.In the present paper the Lindelöf number and the degree of compactness of spaces and of the cozero-dimensional kernel of paracompact spaces are characterized in terms of selections of ...
Mihaylova, Ekaterina P. +2 more
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Applications of δ‐Open Sets via Separation Axioms, Covering Properties, and Rough Set Models
Journal of Mathematics, Volume 2025, Issue 1, 2025.In this article, we make use of δ‐open sets to establish some topological concepts related to separation axioms and covering properties and to propose novel topological rough set models. We first demonstrate that the classes of regular‐open and δ‐open subsets of a finite topological space are equivalent when this space has the property of ∂(A)∩∂(B)⊆∂(A
Tareq M. Al-Shami +2 more
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International Journal of Mathematics and Mathematical Sciences, Volume 13, Issue 3, Page 507-512, 1990., 1989 An ideal on a set X is a nonempty collection of subsets of X closed under the operations of subset (heredity) and finite unions (additivity). Given a topological space (X, τ) an ideal ℐ on X and A⊆X, ψ(A) is defined as ⋃{U ∈ τ : U − A ∈ ℐ}. A topology, denoted τ*, finer than τ is generated by the basis {U − I : U ∈ τ, I ∈ ℐ}, and a topology, denoted 〈ψ(
T. R. Hamlett, David Rose
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A topological property of β(N)
International Journal of Mathematics and Mathematical Sciences, Volume 3, Issue 4, Page 713-717, 1980., 1980 In this paper we prove that the Stone‐Cech‐compactification of the natural numbers does not admit a countable infinite decomposition into subsets homeomorphic to each other and to the said compactification.
Anastase Nakassis
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A short note on nearly perfect maps of locales
, 2017 We characterise compact locales in terms of nearly perfect maps. We show in particular that these maps are the natural pointfree version of Bourbaki's proper maps - when defined via any ultrafillter - and that they extend Herrlich's notion of nearly ...
Razafindrakoto, Ando
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, 2005 We define various notions of boundedness in frames along the lines of similar concepts for subspaces and give characterizations of these in terms of filters.
Dube, Themba
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