On a congruence for the number of finite marked topologies
On almost quasicontinuous functions
A function is said to be almost quasicontinuous at if for each neighbourhood of . Some properties of these functions are investigated.
On Almost-Tractable Spaces I
On almost-tractable spaces I.
On compact spaces which are unions of certain collections of subspaces of special type
On continuous images of almost Tychonoff cubes
On -sequentially regular spaces
On Frolík’s characterization of class
On Inverse Limit Of Function Spaces
On lattice-topological properties of general Wallman spaces.
On locally H-closed spaces and the Fomin H-closed extension
On maps of spaces determined by countable subspaces
On paracompact locales and metric locales
On pseudo-radial spaces
On pushing out frames
On semi-closed sets and semi-open sets and their applications
On spaces in which every denumerable subspaces is discrete
On subspaces of pseudo-radial spaces
It is proved that, under the Martin’s Axiom, every -space with countable tightness is a subspace of some pseudo-radial space. We also give several characterizations of subspaces of pseudo-radial spaces and conclude that being a subspace of a pseudo-radial space is a local property.
On the Baire order of concentrated spaces and spaces
On the open-open game
We modify a game due to Berner and Juhász to get what we call “the open-open game (of length ω)”: a round consists of player I choosing a nonempty open subset of a space X and II choosing a nonempty open subset of I’s choice; I wins if the union of II’s open sets is dense in X, otherwise II wins. This game is of interest for ccc spaces. It can be translated into a game on partial orders (trees and Boolean algebras, for example). We present basic results and various conditions under which I or II...