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$\sigma$-compact (Definition)

A topological space is $ \sigma$-compact if it is a countable union of compact sets.



"$\sigma$-compact" is owned by Koro.
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Other names:  sigma-compact, sigma compact, $\sigma$ compact

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every $\sigma$-compact set is Lindelöf (Theorem) by joen235
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Cross-references: compact sets, union, countable, topological space
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This is version 2 of $\sigma$-compact, born on 2003-12-29, modified 2006-09-13.
Object id is 5503, canonical name is SigmaCompact.
Accessed 4686 times total.

Classification:
AMS MSC: 54D45 (General topology :: Fairly general properties :: Local compactness, $\sigma$-compactness)
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