6 papers
Velichko's notions close to sequentially separability and their hereditary variants in -theory
Alexander V. Osipov
A space is sequentially separable if there is a countable such that every point of is the limit of a sequence of points from . In 2004, N.V. Velichko define…
Joint continuity in semitopological monoids and semilattices
Alexander V. Osipov, Konstantin Kazachenko
In this paper we study the separately continuous actions of semitopological monoids on pseudocompact spaces. The main aim of this paper is to generalize Lawson's results to some cl…
Some observations on a clopen version of the Rothberger property
Manoj Bhardwaj, Alexander V. Osipov
In this paper, we proved that a clopen version of the Rothberger property and Borel strong measure zeroness are independent. For a zero-dimensional metric space $(X…
Covering games using semi-open sets
Manoj Bhardwaj, Alexander V. Osipov
In this paper, we prove the following Theorems 1. An extremally disconnected space has the semi-Menger property if and only if One does not have a winning strategy in the game…
The projectively Hurewicz property is t-invariant
Alexander V. Osipov
A space is projectively Hurewicz provided every separable metrizable continuous image of is Hurewicz. In this paper we prove that the projectively Hurewicz property is -…
Frechet-Urysohn property of quasicontinuous functions
Alexander V. Osipov
The aim of this paper is to study the Frechet-Urysohn property of the space of real-valued quasicontinuous functions, defined on a Hausdorff space , endowed…