G-delta subset: Difference between revisions
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==Definition== | ==Definition== | ||
A subset of a [[topological space]] is termed a <math>G_\delta</math> subset if it is expressible as a countable intersection of open | A subset of a [[topological space]] is termed a <math>G_\delta</math> subset if it is expressible as a countable intersection of [[open subset]]s. | ||
==Relation with other properties== | ==Relation with other properties== | ||
Revision as of 08:33, 18 August 2007
This article defines a property over pairs of a topological space and a subspace, or equivalently, properties over subspace embeddings (viz, subsets) in topological spaces
Definition
A subset of a topological space is termed a subset if it is expressible as a countable intersection of open subsets.
Relation with other properties
Stronger properties
Related properties
There are related notions captured in the G hierarchy and F hierarchy