KnowraVon Neumann–Bernays–Gödel set theoryLinked fromLinked fromThe 5 pages that link to Von Neumann–Bernays–Gödel set theory, each with the reason it gives.All 5Related 3Compared with 2Zermelo–Fraenkel set theoryCompared with: It offers explicit class language while remaining closely related in strength to ZF.Russell's paradoxRelated: It permits a class of all non-self-membered sets without treating that class as a set.Von Neumann universeCompared with: It formalizes the universe as a proper class alongside its sets.Axiom of global choiceRelated: It formalizes classes and permits a precise statement of the global choice axiom.Axiom of limitation of sizeRelated: NBG uses limitation of size to distinguish proper classes from sets.