Smulian-Eberlein Spaces
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.
Given a subbase of a space , the game is defined for two players and who respectively pick, at the -th move, a point and a set such that . The game stops after the moves have been made and the player wins if ; otherwise is the winner. Since is an evident modification of the well-known point-open game , the primary line of research is to describe the relationship between and for a given subbase . It turns out that, for any subbase , the player has a winning strategy...
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.