On c-closed functions
On certain generalizations of the notion of continuity
On character and chain conditions in images of products
A scadic space is a Hausdorff continuous image of a product of compact scattered spaces. We complete a theorem begun by G. Chertanov that will establish that for each scadic space X, χ(X) = w(X). A ξ-adic space is a Hausdorff continuous image of a product of compact ordinal spaces. We introduce an either-or chain condition called Property which we show is satisfied by all ξ-adic spaces. Whereas Property is productive, we show that a weaker (but more natural) Property is not productive. Polyadic...
On completely continuous mappings
On decomposition of fuzzy -continuity.
On decomposition of projections of finite order
On f.p.p. and f.*p.p. of some not locally connected continua
On functions with the set of discontinuity points belonging to some -ideal
On fuzzy strongly α-Continuous Functions
On Hattori spaces
For a subset of the real line , Hattori space is a topological space whose underlying point set is the reals and whose topology is defined as follows: points from are given the usual Euclidean neighborhoods while remaining points are given the neighborhoods of the Sorgenfrey line. In this paper, among other things, we give conditions on which are sufficient and necessary for to be respectively almost Čech-complete, Čech-complete, quasicomplete, Čech-analytic and weakly separated (in...
On locally connected plane one-to-one continuous images of [0,∞)
On mappings preserving a family of star bodies.
On maps: Continuous, closed, perfect, and with closed graph.
On maps preserving connectedness and/or compactness
We call a function P-preserving if, for every subspace with property P, its image also has property P. Of course, all continuous maps are both compactness- and connectedness-preserving and the natural question about when the converse of this holds, i.e. under what conditions such a map is continuous, has a long history. Our main result is that any nontrivial product function, i.e. one having at least two nonconstant factors, that has connected domain, range, and is connectedness-preserving...
On nowhere density of the class of somewhat continuous functions in
On pseudocompact, countably compact, locally bicompact mappings, and -mappings.
On quasi -open and quasi -closed functions.
On quasicontinuity of multifunctions
On reflexive closed set lattices
For a topological space , let denote the set of all closed subsets in , and let denote the set of all continuous maps . A family is called reflexive if there exists such that for every . Every reflexive family of closed sets in space forms a sub complete lattice of the lattice of all closed sets in . In this paper, we continue to study the reflexive families of closed sets in various types of topological spaces. More necessary and sufficient conditions for certain families of closed...
On semi-closed sets and semi-open sets and their applications