On and weakly- spaces.
On Pixley-Roy hyperspaces
On powers of Lindelöf spaces
We present a forcing construction of a Hausdorff zero-dimensional Lindelöf space whose square is again Lindelöf but its cube has a closed discrete subspace of size , hence the Lindelöf degree . In our model the Continuum Hypothesis holds true. After that we give a description of a forcing notion to get a space such that for all positive integers , but .
On Preservation Of Normality.
On products of incompressible AR's
On products of pseudoradial ѕpaces
On projectively quotient functors
We introduce notions of projectively quotient, open, and closed functors. We give sufficient conditions for a functor to be projectively quotient. In particular, any finitary normal functor is projectively quotient. We prove that the sufficient conditions obtained are necessary for an arbitrary subfunctor of the functor of probability measures. At the same time, any “good” functor is neither projectively open nor projectively closed.
On proximity ordered spaces
On PSigma and Weakly PSigma Spaces
On pushing out frames
On reflexive closed set lattices
For a topological space , let denote the set of all closed subsets in , and let denote the set of all continuous maps . A family is called reflexive if there exists such that for every . Every reflexive family of closed sets in space forms a sub complete lattice of the lattice of all closed sets in . In this paper, we continue to study the reflexive families of closed sets in various types of topological spaces. More necessary and sufficient conditions for certain families of closed...
On shape and fundamental deformation retracts II
On shape of hyperspaces
On some maps concerning -open sets.
On some metrizations of the hyperspace of compact sets
On some operation on sets of mappings
On some spaces which are covered by a product space
In this note, a topological version of the results obtained, in connection with the de Rham reducibility theorem (Comment. Math. Helv., 26 ( 1952), 328–344), by S. Kashiwabara (Tôhoku Math. J., 8 (1956), 13–28), (Tôhoku Math. J., 11 (1959), 327–350) and Ia. L. Sapiro (Izv. Bysh. Uceb. Zaved. Mat. no6, (1972), 78–85, Russian), (Izv. Bysh. Uceb. Zaved. Mat. no4, (1974), 104–113, Russian) is given. Thus a characterization of a class of topological spaces covered by a product space is obtained and the...
On Some Spaces which can be Partioned by the Rational Line.
On some subspaces of the Helly space
On spaces whose product with every Lindelöf space is Lindelöf