On monotone mappings of continua
On monotone minimal cuscos
On movability and other similar shape properties
On movable compacta
On multifunctions with closed graphs
The set of points of upper semicontinuity of multi-valued mappings with a closed graph is studied. A topology on the space of multi-valued mappings with a closed graph is introduced.
On multifunctions with convex graph
In questa Nota viene stabilita una caratterizzazione generale della semicontinuità inferiore delle multifunzioni, a grafico convesso, definite in sottoinsieme non vuoto, aperto e convesso di uno spazio vettoriale topologico e a valori in uno spazio vettoriale topologico localmente convesso. Sono poste in luce, poi, varie conseguenze di tale caratterizzazione.
On multivalued quotient mappings
On multivalued quotient mappings.
On N. Noble's theorems concerning powers of spaces and mappings
On non compact FANR's and MANR's
On nonregular ideals and -ideals in
The spaces in which every prime -ideal of is either minimal or maximal are characterized. By this characterization, it turns out that for a large class of topological spaces , such as metric spaces, basically disconnected spaces and one-point compactifications of discrete spaces, every prime -ideal in is either minimal or maximal. We will also answer the following questions: When is every nonregular prime ideal in a -ideal? When is every nonregular (prime) -ideal in a -ideal? For...
On non-separable 0-dimensional metrizable spaces
On nowhere density of the class of somewhat continuous functions in
On open light mappings
Whyburn has proved that each open mapping defined on arc (a simple closed curve) is light. Charatonik and Omiljanowski have proved that each open mapping defined on a local dendrite is light. Theorem 3.8 is an extension of these results.
On open maps of Borel sets
We answer in the affirmative [Th. 3 or Corollary 1] the question of L. V. Keldysh [5, p. 648]: can every Borel set X lying in the space of irrational numbers ℙ not and of the second category in itself be mapped onto an arbitrary analytic set Y ⊂ ℙ of the second category in itself by an open map? Note that under a space of the second category in itself Keldysh understood a Baire space. The answer to the question as stated is negative if X is Baire but Y is not Baire.
On oscillation of limit functions.
On and weakly- spaces.
On pairs of compacta with dim(X×Y) < dimX + dimY
On pairwise super continuous mappings in bitopological spaces.
On Paracompactness and Almost Closed Mappings