A remark on a paper by Karel Prikry
S. Solecki proved that if is a system of closed subsets of a complete separable metric space , then each Suslin set which cannot be covered by countably many members of contains a set which cannot be covered by countably many members of . We show that the assumption of separability of cannot be removed from this theorem. On the other hand it can be removed under an extra assumption that the -ideal generated by is locally determined. Using Solecki’s arguments, our result can be used...
In this paper, we present a representation theorem for probabilistic metric spaces in general.
Using ♢ , we construct a rigid atomless Boolean algebra that has no uncountable antichain and that admits the elimination of the Malitz quantifier .
In this paper we develop the semifilter approach to the classical Menger and Hurewicz properties and show that the small cardinal is a lower bound of the additivity number of the -ideal generated by Menger subspaces of the Baire space, and under every subset of the real line with the property is Hurewicz, and thus it is consistent with ZFC that the property is preserved by unions of less than subsets of the real line.
Developing the idea of assigning to a large cover of a topological space a corresponding semifilter, we show that every Menger topological space has the property provided , and every space with the property is Hurewicz provided . Combining this with the results proven in cited literature, we settle all questions whether (it is consistent that) the properties and [do not] coincide, where and run over , , , , and .