Collectionwise normal space: Difference between revisions

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===Symbol-free definition===
===Symbol-free definition===


A topological space is termed '''collectionwise normal''' if given any ''discrete'' collection of closed sets (viz., a disjoint collection of closed sets such that each is open in their union), there exists a family of pairwise disjoint open sets containing each of the closed sets.
A topological space is termed '''collectionwise normal''' if it is [[T1 space|T1]] and, given any ''discrete'' collection of closed sets (viz., a disjoint collection of closed sets such that each is open in their union), there exists a family of pairwise disjoint open sets containing each of the closed sets.


==Relation with other properties==
==Relation with other properties==

Revision as of 20:14, 15 December 2007

This article defines a property of topological spaces: a property that can be evaluated to true/false for any topological space|View a complete list of properties of topological spaces

This is a variation of normality. View other variations of normality

Definition

Symbol-free definition

A topological space is termed collectionwise normal if it is T1 and, given any discrete collection of closed sets (viz., a disjoint collection of closed sets such that each is open in their union), there exists a family of pairwise disjoint open sets containing each of the closed sets.

Relation with other properties

Stronger properties

Weaker properties