*σ*-algebra

Definition from Wiktionary, the free dictionary

## English[edit]

### Pronunciation[edit]

- IPA
^{(key)}: /ˈsɪɡ.mə ˈæl.dʒɪ.bɹə/

### Noun[edit]

** σ-algebra** (

*plural*

**σ-algebras**)

- (analysis) A collection of subsets of a given set, such that the empty set is part of this collection, the collection is closed under complements (with respect to the given set) and the collection is closed under countable unions.