On some bitopological applications
On some combinatorial problems in uniform spaces
On some covering properties of metric spaces
On some dense subspaces of topological linear spaces
On some fixed point theorems in Banach spaces.
On some metrizations of the hyperspace of compact sets
On some properties of bitopological semi-separate spaces
On some properties of hyperconvex spaces.
On some properties of proximity in metric spaces
On some property of the tangency relation of sets.
On some questions in quasi-uniform topological spaces.
Partial solution is given here respect to one open problem posed by P. Fletcher and W. F. Lindgren in their monography Quasi-uniform spaces.
On some subspaces of the Helly space
On some topologies on a generalized metric space.
On spaces which have the shape of C. W. complexes
On spaces which have the shape of compact metric spaces
On spaces with point-countable -systems
This paper deals with the behavior of -spaces, countably bi-quasi--spaces and singly bi-quasi--spaces with point-countable -systems. For example, we show that every -space with a point-countable -system is locally compact paracompact, and every separable singly bi-quasi--space with a point-countable -system has a countable -system. Also, we consider equivalent relations among spaces entried in Table 1 in Michael’s paper [15] when the spaces have point-countable -systems.
On special metrics characterizing topological properties
On stratifiable fuzzy topological spaces
The aim of the paper is to extend the notion of stratifiability from the category Top of topological spaces to the category CFT of [Chang] fuzzy topological spaces and to develop the corresponding theory.
On subcompactness and countable subcompactness of metrizable spaces in ZF
We show in ZF that: (i) Every subcompact metrizable space is completely metrizable, and every completely metrizable space is countably subcompact. (ii) A metrizable space is countably compact if and only if it is countably subcompact relative to . (iii) For every metrizable space , the following are equivalent: (a) is compact; (b) for every open filter of , ; (c) is subcompact relative to . We also show: (iv) The negation of each of the statements, (a) every countably subcompact metrizable...
On subsets of Alexandroff duplicates
We characterize the subsets of the Alexandroff duplicate which have a G-diagonal and the subsets which are M-spaces in the sense of Morita.