Closed set: Difference between revisions

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A set <math>A \subset X</math>, where <math>(X,O)</math> is some [[topological space]], is said to be closed if <math>X-A=\{x \in X \mid x \notin A\}</math>, the complement of <math>X</math> in <math>A</math>, is an [[open set]]
A set <math>A \subset X</math>, where <math>(X,O)</math> is some [[topological space]], is said to be closed if <math>X-A=\{x \in X \mid x \notin A\}</math>, the complement of <math>A</math> in <math>X</math>, is an [[open set]]


== See also ==
== See also ==

Revision as of 08:06, 31 August 2007

A set , where is some topological space, is said to be closed if , the complement of in , is an open set

See also

Analysis