σ-algebra


Let X be a set. A σ-algebra is a collectionMathworldPlanetmath M of subsets of X such that

  • XM

  • If AM then X-AM.

  • If A1,A2,A3, is a countableMathworldPlanetmath subcollection of M, that is, AjM for j=1,2,3, (the subcollection can be finite) then the union of all of them is also in M:

    j=1AiM.
Title σ-algebra
Canonical name sigmaalgebra
Date of creation 2013-03-22 14:00:04
Last modified on 2013-03-22 14:00:04
Owner drini (3)
Last modified by drini (3)
Numerical id 7
Author drini (3)
Entry type Definition
Classification msc 28A60