Results 31 to 40 of about 66 (64)
γ‐sets and γ‐continuous functions
International Journal of Mathematics and Mathematical Sciences, Volume 31, Issue 3, Page 177-181, 2002., 2002 We introduce a new class of sets, called γ‐sets, and the notion of γ‐continuity and investigate some properties and characterizations. In particular, γ‐sets and γ‐continuity are used to extend known results for semi‐open sets and semi‐continuity.
Won Keun Min
wiley +1 more source
International Journal of Mathematics and Mathematical Sciences, Volume 28, Issue 5, Page 285-292, 2001., 2001 We introduce a new class of functions called θ‐precontinuous functions which is contained in the class of weakly precontinuous (or almost weakly continuous) functions and contains the class of almost precontinuous functions. It is shown that the θ‐precontinuous image of a p‐closed space is quasi H‐closed.
Takashi Noiri
wiley +1 more source
Slightly β‐continuous functions
International Journal of Mathematics and Mathematical Sciences, Volume 28, Issue 8, Page 469-478, 2001., 2001 We define a function f : X → Y to be slightly β‐continuous if for every clopen set V of Y, f−1(V) ⊂ Cl(Int(Cl(f−1(V)))). We obtain several properties of such a function. Especially, we define the notion of ultra‐regularizations of a topology and obtain interesting characterizations of slightly β‐continuous functions by using it.
Takashi Noiri
wiley +1 more source
On almost precontinuous functions
International Journal of Mathematics and Mathematical Sciences, Volume 24, Issue 3, Page 193-201, 2000., 2000 Nasef and Noiri (1997) introduced and investigated the class of almost precontinuous functions. In this paper, we further investigate some properties of these functions.
Saeid Jafari, Takashi Noiri
wiley +1 more source
(I , γ)-generalized semi-closed sets in topological spaces
, 2010 In this paper we introduce (I , ?)-generalized semi-closed sets in topological spaces and also introduce ?S - TI-spaces and investigate some of their properties. 2010 Mathematics Subject Classifications. 54B05, 54C08, 54D05. .
A. Selvakumar, R. Devi, M. Vigneshwaran
core +1 more source
International Journal of Mathematics and Mathematical Sciences, Volume 22, Issue 2, Page 239-249, 1999., 1999 The aim of this paper is to study the class of θ‐generalized closed sets, which is properly placed between the classes of generalized closed and θ‐closed sets. Furthermore, generalized Λ‐sets [16] are extended to θ‐generalized Λ‐sets and R0‐, T1/2‐ and T1‐spaces are characterized.
Julian Dontchev, Haruo Maki
wiley +1 more source
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
wiley +1 more source
Contra‐continuous functions and strongly S‐closed spaces
International Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 2, Page 303-310, 1996., 1996 In 1989 Ganster and Reilly [6] introduced and studied the notion of LC‐continuous functions via the concept of locally closed sets. In this paper we consider a stronger form of LC‐continuity called contra‐continuity. We call a function f : (X, τ) → (Y, σ) contra‐continuous if the preimage of every open set is closed. A space (X, τ) is called strongly S‐
J. Dontchev
wiley +1 more source
Filter Bases and j-ω-Perfect Mappings
Ibn Al-Haitham Journal for Pure and Applied Sciences, 2019 This paper consist some new generalizations of some definitions such: j-ω-closure converge to a point, j-ω-closure directed toward a set, almost j-ω-converges to a set, almost j-ω-cluster point, a set j-ω-H-closed relative, j-ω-closure ...
G. S. Ashaea, Y. Y. Yousif
doaj +1 more source
On functions determined by limit sets and the quasi-Świątkowski property
, 2021 We introduce and investigate the class of functions determined by limit sets for which at each point the intersection of the sets of left-hand and right-hand limit numbers is singleton containing value of function at this point.
Chmielewska, Kataryzna +1 more
core