{"version":"1.0","type":"link","title":"Delta-ring - Newikis","description":"In mathematics, a non-empty collection of sets is called a δ-ring (pronounced \"delta-ring\") if it is closed under union, relative complementation, and countable intersection. The name \"delta-ring\" originates from the German word for intersection, \"Durchschnitt\", which is meant to highlight the…","provider_name":"Newikis","provider_url":"https://newikis.com","cache_age":86400}