Small systems – on approximation of compact sets of measurable functions to compact subsets of
Smooth structures on
Sober spaces and continuations.
Sobre compactificaciones de Wallman-Frink de espacios discretos.
Dado un espacio T3α (X,T), es posible obtener una compactificación T2 del mismo, mediante ultrafiltros asociados a ciertas bases distinguidas de cerrados de (X,T) (Frink [4]). Se plantea así el problema siguiente: ¿Puede obtenerse toda compactificación T2 de (X,T) por este método? Desde el año 1964 en que Frink lo planteó, este interrogante ha tenido respuestas afirmativas parciales. Sin embargo, la solución definitiva es negativa.
Sobre el teorema de inmersión de Mrówka.
Certain equivalences of Mrowka's separating condition enable us to characterize when parametric maps are open, closed or quotient.
Solution du problème de point fixe de Schauder
We give an affirmative answer to Schauder's fixed point question.
Solution d'un probleme de Fadell sur les fibres
Let E be the total space of a Hurewicz fiber space whose base and all fibers are ANRs. We prove that if E is metrisable, then it is also an ANR.
Solution d'une question de H. Weizsächer
Solution of Kuratowski's problem on function having the Baire property, I
Some characterization of c-paracompact and c-collectionwise normal spaces by continuous selections (II).
Some characterizations of bitopological connectivity properties
Some characterizations of c-paracompact and c-collectionwise normal spaces by continuous selections (I).
In this note we characterize the c-paracompact and c-collectionwise normal spaces in terms of continuous selections. We include the usual techniques with the required modifications by the cardinality.
Some characterizations of open, closed, and continuous mappings.
Some classes of locally connected continua
Some Comments on Q-Irresolute and Quasi-Irresolute Functions
The aim of this paper is to continue the study of θ-irresolute and quasi-irresolute functions as well as to give an example of a function which is θ-irresolute but neither quasi-irresolute nor an R-map and thus give an answer to a question posed by Ganster, Noiri and Reilly. We prove that RS-compactness is preserved under open, quasi-irresolute surjections.
Some constructive topological properties of function spaces
Some embeddings of weighted Sobolev spaces on finite measure and quasibounded domains.
Some examples of d-ideals and related Baire systems
Some examples of irreducibly confluent mappings
Some examples related to colorings
We complement the literature by proving that for a fixed-point free map the statements (1) admits a finite functionally closed cover with for all (i.e., a coloring) and (2) is fixed-point free are equivalent. When functionally closed is weakened to closed, we show that normality is sufficient to prove equivalence, and give an example to show it cannot be omitted. We also show that a theorem due to van Mill is sharp: for every we construct a strongly zero-dimensional Tychonov space...