Number of open sets for a topology with a countable basis
Logic
2008-02-03 v1 General Topology
Abstract
Let T be the family of open subsets of a topological space (not necessarily Hausdorff or even T_0). We prove that if T has a countable base and is not countable, then T has cardinality at least continuum.
Keywords
Cite
@article{arxiv.math/9308217,
title = {Number of open sets for a topology with a countable basis},
author = {Saharon Shelah},
journal= {arXiv preprint arXiv:math/9308217},
year = {2008}
}