×

zbMATH — the first resource for mathematics

Filters and ultrafilters. (Filtres et ultrafiltres.) (French) Zbl 0018.00302
This is a sequel to an earlier note on “filters” [C. R. Acad. Sci., Paris 205, 595–598 (1937; Zbl 0017.24305)]. The author characterizes compact spaces in terms of filters – a necessary and sufficient for compactness is that every “ultrafilter” be convergent. He characterizes continuous maps in terms of filters also.

MSC:
54-XX General topology
PDF BibTeX XML Cite