paper

Combinatorial and model-theoretical principles related to regularity of ultrafilters and compactness of topological spaces. II

arXiv:0804.1445

Abstract

We find many conditions equivalent to the model-theoretical property introduced in [L1]. Our conditions involve uniformity of ultrafilters, compactness properties of products of topological spaces and the existence of certain infinite matrices.

5 pages

Combinatorial and model-theoretical principles related to regularity of ultrafilters and compactness of topological spaces. II · wovepaper