A family of sets is called a δ-ring if it has all of the following properties:
- Closed under finite unions: for all
- Closed under relative complementation: for all and
- Closed under countable intersections: if for all
The family is a δ-ring but not a σ-ring because is not bounded.
- Cortzen, Allan. "Delta-Ring." From MathWorld—A Wolfram Web Resource, created by Eric W. Weisstein. http://mathworld.wolfram.com/Delta-Ring.html
|This mathematical analysis–related article is a stub. You can help Wikipedia by expanding it.|