Results 11 to 20 of about 61 (61)
Measure of nonhyperconvexity and fixed‐point theorems
Abstract and Applied Analysis, Volume 2003, Issue 2, Page 111-119, 2003., 2003 The aim of this paper is to work with the measure of nonhyperconvexity in a similar way as J. Cano (1990) does with the index of nonconvexity. We apply this measure to obtain different extensions of the famous Schauder fixed‐point theorem in hyperconvex spaces.
Dariusz Bugajewski, Rafael Espínola
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Quasi‐pseudometrizability of the point open ordered spaces and the compact open ordered spaces
International Journal of Mathematics and Mathematical Sciences, Volume 26, Issue 7, Page 385-392, 2001., 2001 We determine conditions for quasi‐pseudometrizability of the point open ordered spaces and the compact open ordered spaces. This generalizes the results on metrizability of the point open topology and the compact open topology for function spaces. We also study conditions for complete quasi‐pseudometrizability.
Koena Rufus Nailana
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A subset of metric preserving functions
International Journal of Mathematics and Mathematical Sciences, Volume 21, Issue 2, Page 409-410, 1998., 1996 In this paper we define a subset of metric preserving functions and give some examples and a characterization ofthis subset.
Robert W. Vallin
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On the inverse image of Baire spaces
International Journal of Mathematics and Mathematical Sciences, Volume 20, Issue 3, Page 423-432, 1997., 1996 In 1961, Z. Frolik proved that if f is an open and continuous mapping of a metrizable separable space X onto Baire space Y and if the point inverses are Baire spaces, then X is a Baire space. We give a generalization to semi‐continuous and semi‐open mapping of this theorem and extended it to the several types of mappings.
Mustafa Çiçek
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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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A note on maximally resolvable spaces
International Journal of Mathematics and Mathematical Sciences, Volume 13, Issue 3, Page 513-516, 1990., 1989 A.G. El′kin [1] poses the question as to whether any uncountable cardinal number can be the dispersion character of a Hausdorff maximally resolvable space. In this note we prove that every cardinal number ℵ ≥ ℵ1 can be the dispersion character of a metric (hence, maximally resolvable) connected, locally connected space.
V. Tzannes
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A quasitopos containing CONV and MET as full subcategories
International Journal of Mathematics and Mathematical Sciences, Volume 11, Issue 3, Page 417-438, 1988., 1987 We show that convergence spaces with continuous maps and metric spaces with contractions, can be viewed as entities of the same kind. Both can be characterized by a limit function λ which with each filter ℱ associates a map λℱ from the underlying set to the extended positive real line. Continuous maps and contractions can both be characterized as limit
E. Lowen, R. Lowen
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On q`‐Rung Orthopair Neutrosophic Metric Spaces and Topological Properties
Journal of Applied Mathematics, Volume 2025, Issue 1, 2025.In this paper, we introduce the novel structure of the q`‐rung orthopair neutrosophic metric space (q`‐RˇONM∧S), which unifies and extends the frameworks of q`‐rung orthopair fuzzy sets and neutrosophic metric spaces. The proposed model incorporates membership, nonmembership, and indeterminacy degrees within a q`‐rung orthopair framework, thereby ...
N. Muthulakshmi +4 more
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Journal of Mathematics, Volume 2025, Issue 1, 2025.In this study, we introduce a bipolar interval‐valued intuitionistic fuzzy (BIVIF) norm, projection, and bidirectional projection measure within the framework of BIVIF topological spaces. These tools enable us to handle ambiguity with greater accuracy, calculate relationships between sets more effectively, and make rational decisions in uncertain ...
Suganya Manivannan +4 more
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On monoids of metric preserving functions
Frontiers in Applied Mathematics and StatisticsLet X be a class of metric spaces and let PX be the set of all f : [0, ∞) → [0, ∞) preserving X, i.e., (Y, f ∘ ρ) ∈ X whenever (Y, ρ) ∈ X. For arbitrary subset A of the set of all metric preserving functions, we show that the equality PX = A has a ...
Viktoriia Bilet +2 more
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