Results 41 to 50 of about 66 (64)
On the theorems of Y. Mibu and G. Debs on separate continuity
International Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 3, Page 495-500, 1996., 1995 Using a game‐theoretic characterization of Baire spaces, conditions upon the domain and the range are given to ensure a fat set C(f) of points of continuity in the sets of type X × {y}, y ∈ Y for certain almost separately continuous functions f : X × Y → Z. These results (especially Theorem B) generalize Mibu′s.
Zbigniew Piotrowski
wiley +1 more source
Semi-quotient mappings and spaces
Open Mathematics, 2016 In this paper, we continue the study of s-topological and irresolute-topological groups. We define semi-quotient mappings which are stronger than semi-continuous mappings, and then consider semi-quotient spaces and groups.
Khan Moiz ud Din +2 more
doaj +1 more source
Separating sets by bilaterally quasi-continuous functions
, 2021 In this paper we characterize the pairs (A0;A1) and (A-, A+) of disjoint sets which can be separated by a bilaterally quasi-continuous function. Moreover, we characterize when two arbitrary subsets of the real line can be separated by bilaterally dense ...
Syzsykowska, Paulina
core
A note on weakly quasi continuous functions
International Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 4, Page 767-772, 1996., 1995 The notion of weakly quasi continuous functions introduced by Popa and Stan [1]. In this paper, the authors obtain the further properties of such functions and introduce weak* quasi continuity which is weaker than semi continuity [2] but independent ofweak quasi continuity.
Jin Han Park, Hoe Young Ha
wiley +1 more source
Note on limits of simply continuous and cliquish functions
International Journal of Mathematics and Mathematical Sciences, Volume 17, Issue 3, Page 447-450, 1994., 1993 The main result of this paper is that any function f defined on a perfect Baire space (X, T) with values in a separable metric space Y is cliquish (has the Baire property) iff it is a uniform (pointwise) limit of sequence {fn : n ≥ 1} of simply continuous functions. This result is obtained by a change of a topology on X and showing that a function f : (
Janina Ewert
wiley +1 more source
Diagonals of separately continuous maps with values in box products
Topological Algebra and its Applications, 2018 We prove that if X is a paracompact connected space and Z = ∏s∈S Zs is a product of a family of equiconnected metrizable spaces endowed with the box topology, then for every Baire-one map g : X → Z there exists a separately continuous map f : X2 → Z such
Karlova Olena, Mykhaylyuk Volodymyr
doaj +1 more source
Weak C-embedding and P -embedding, and product spaces [PDF]
, 2002 Arhangel'skiȋ defines in [Topology Appl. 70 (1996) [Topology Appl. 93 (1999) 121-129]. Moreover, suggested by weak C-embedding, we define a notion of weak Pembedding, more precisely, weak P γ -embedding for an infinite cardinal γ , which is an ...
Kaori Yamazaki, Takao Hoshina
core
Extensions of semicontinuous and quasi-continuous functions from dense subspaces
, 2021 In this paper we give a sufficient condition for existence of an extension of a lower (upper) semicontinuous function 0 defined on a given dense subset of a topological space X to a lower (upper) semicontinuous function : X → ℝ.
Kosman, Jolanta
core
Weakly (I, J)-continuous multifunctions and contra (I, J)-continuous multifunctions [PDF]
, 2019 The purpose of the present paper is to introduce, study and characterize upper and lower weakly (I, J)-continuous multifunctions and contra (I, J)-continuous multifunctions.
Rosas Rodriguez, Ennis Rafael +3 more
core
Separating sets by lower and upper semicontinuous functions with a closed graph
, 2016 In this paper we characterize the pairs (A- ;A+) of disjoint subsets of perfectly normal topological space which can be separated by a lower and an upper semicontinuous function with a closed graph.Mathematics Subject Classification (2010): 54C30, 26A15,
Kosman, Jolanta
core