Number of open sets for a topology with a countable basis

Saharon Shelah

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arXiv · math/9308217

Number of open sets for a topology with a countable basis

Saharon Shelah

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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.

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BibTeX RIS

Saharon Shelah. 1993-08-15. Number of open sets for a topology with a countable basis. https://arxiv.org/abs/math/9308217

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