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...
On tightness in chain-net spaces
On topological ergodic measure spaces.
On -generalized closed sets.
Oб одной задаче Э. Чеха
Prime extensions and nearness structures
Productively Fréchet spaces
We solve the long standing problem of characterizing the class of strongly Fréchet spaces whose product with every strongly Fréchet space is also Fréchet.
Quasi-radicals and Radicals in Categories
Rapport entre l'ensemble des ultrafiltres admettant un ultrafiltre donné pour image et l'ensemble des images de cet ultrafiltre
Rational spaces and the property of universality