On the tightness of chain-net spaces
On topologies generating the Effros Borel structure and on the Effros measurability of the boundary operation
On totally non-commutative convergence groupoids
On transfinite convergence and generalized continuity
On weakly bisequential spaces
Weakly bisequential spaces were introduced by A.V. Arhangel'skii [1], in this paper. We discuss the relations between weakly bisequential spaces and metric spaces, countably bisequential spaces, Fréchet-Urysohn spaces.
On -regular spaces.
One-point compactification on convergence spaces.
Open and proper maps between convergence spaces
Open maps do not preserve Whyburn property
We show that a (weakly) Whyburn space may be mapped continuously via an open map onto a non (weakly) Whyburn space . This fact may happen even between topological groups and , a homomorphism, Whyburn and not even weakly Whyburn.
Order compatibility for Cauchy spaces and convergence spaces.
Ordered Cauchy spaces.
Oб одной задаче Э. Чеха