Axiom of Foundation

GPTKB entity

Statements (20)
Predicate Object
gptkbp:instanceOf gptkb:Titan
gptkb:set_theory
gptkbp:alsoKnownAs gptkb:Axiom_of_regularity
gptkbp:contrastsWith Non-well-founded set theory
gptkbp:formedBy gptkb:John_von_Neumann
1922
https://www.w3.org/2000/01/rdf-schema#label Axiom of Foundation
gptkbp:implies Set membership is well-founded
gptkbp:introducedIn gptkb:Zermelo-Fraenkel_set_theory
gptkbp:partOf gptkb:Zermelo-Fraenkel_set_theory
gptkbp:prevention Infinite descending membership chains
Sets containing themselves as members
gptkbp:state Every non-empty set A contains an element that is disjoint from A
gptkbp:symbol ∀A [A ≠ ∅ → ∃B (B ∈ A ∧ B ∩ A = ∅)]
gptkbp:usedIn Standard set theory
gptkbp:bfsParent gptkb:Morse–Kelley_set_theory
gptkb:Axiom_of_Infinity
gptkb:Axiom_of_Regularity
gptkb:Set_Theory
gptkbp:bfsLayer 5