The axiom of extensionality, also called the axiom of extent, is an axiom used in many forms of axiomatic set theory, such as Zermelo–Fraenkel set theory...
14 KB (1,879 words) - 16:29, 24 May 2025
implies both propositional and functional extensionality. Extensionality principles are usually assumed as axioms, especially in type theories where computational...
5 KB (618 words) - 03:46, 5 May 2025
\lnot (u\in u)\}.} Thus, the axiom of the empty set is implied by the nine axioms presented here. The axiom of extensionality implies the empty set is unique...
46 KB (6,252 words) - 13:43, 7 June 2025
assume any axioms except the axiom of extensionality and the axiom of induction—a natural number is either zero or a successor and each of its elements...
11 KB (1,809 words) - 03:54, 21 June 2025
Axiom of extensionality Axiom of empty set Axiom of pairing Axiom of union Axiom of infinity Axiom schema of replacement Axiom of power set Axiom of regularity...
3 KB (270 words) - 21:03, 10 December 2024
axiom of extensionality to show that this set C is unique. We call the set C the pair of A and B, and denote it {A,B}. Thus the essence of the axiom is:...
7 KB (1,148 words) - 13:03, 30 May 2025
x_{n})].} Then the axiom schema of replacement is replaced by a single axiom that uses a class. Finally, ZFC's axiom of extensionality is modified to handle...
97 KB (15,666 words) - 02:01, 18 March 2025
whose members are precisely the members of A that satisfy φ {\displaystyle \varphi } . By the axiom of extensionality this set is unique. We usually denote...
15 KB (2,207 words) - 05:19, 24 March 2025
, the power set of x {\displaystyle x} , consisting precisely of the subsets of x {\displaystyle x} . By the axiom of extensionality, the set P ( x )...
4 KB (633 words) - 21:31, 22 March 2024
Equality (mathematics) (redirect from Reflexive property of equality)
be equal if they have all the same members. This is called the axiom of extensionality. In English, the word equal is derived from the Latin aequālis...
68 KB (7,796 words) - 14:01, 24 June 2025
Kripke–Platek set theory (redirect from Kripke–Platek axioms of set theory)
(See the Lévy hierarchy.) Axiom of extensionality: Two sets are the same if and only if they have the same elements. Axiom of induction: φ(a) being a formula...
10 KB (1,586 words) - 11:54, 3 May 2025
In mathematics, the axiom of regularity (also known as the axiom of foundation) is an axiom of Zermelo–Fraenkel set theory that states that every non-empty...
26 KB (3,247 words) - 15:49, 19 June 2025
words: There is a set such that no element is a member of it. We can use the axiom of extensionality to show that there is only one empty set. Since it is...
6 KB (798 words) - 18:40, 23 August 2024
Ackermann set theory (redirect from Axiom of heredity)
B)\to A=B.} This axiom is identical to the axiom of extensionality found in many other set theories, including ZF. Any element or a subset of a set is a set...
9 KB (1,332 words) - 14:52, 24 June 2025
Zermelo set theory (redirect from Axiom of elementary sets)
predicate. AXIOM I. Axiom of extensionality (Axiom der Bestimmtheit) "If every element of a set M is also an element of N and vice versa ... then M ≡...
15 KB (2,244 words) - 04:47, 5 June 2025
Look up extension, extend, or extended in Wiktionary, the free dictionary. Extension, extend or extended may refer to: Axiom of extensionality Extensible...
4 KB (434 words) - 04:07, 22 April 2025
Non-well-founded set theory (redirect from Axiom of superuniversality)
fail as badly as it can (or rather, as extensionality permits): Boffa's axiom implies that every extensional set-like relation is isomorphic to the elementhood...
12 KB (1,479 words) - 22:03, 1 June 2025
Empty set (section In other areas of mathematics)
existence of the empty set is assured by the axiom of empty set, and its uniqueness follows from the axiom of extensionality. However, the axiom of empty...
15 KB (2,229 words) - 02:12, 26 May 2025
Ernst Zermelo (category Academic staff of the University of Zurich)
Axiom of choice Axiom of constructibility Axiom of extensionality Axiom of infinity Axiom of limitation of size Axiom of pairing Axiom of union Axiom...
12 KB (1,217 words) - 22:39, 25 May 2025
Union (set theory) (redirect from Union of sets)
of the elements of A {\displaystyle A} . Then one can use the axiom of extensionality to show that this set is unique. For readability, define the binary...
14 KB (1,989 words) - 08:46, 6 May 2025
form. In particular the equivalence holds in the presence of the axioms of extensionality, pairing, union and powerset. ∀ A ( [ ∀ x ∃ ! y ϕ ( x , y ...
22 KB (3,558 words) - 04:45, 6 June 2025
the axiom of extensionality must be formulated to apply only to objects that are not urelements. This situation is analogous to the treatments of theories...
8 KB (995 words) - 22:00, 20 November 2024
Tarski–Grothendieck set theory (category Systems of set theory)
ontology as ZFC). Axiom of extensionality: Two sets are identical if they have the same members. Axiom of regularity: No set is a member of itself, and circular...
9 KB (1,135 words) - 12:48, 21 March 2025
S (set theory) (category Systems of set theory)
axiom schema of replacement is derivable in S+ + Extensionality. Hence S+ + Extensionality has the power of ZF. Boolos also argued that the axiom of choice...
9 KB (1,337 words) - 12:56, 27 December 2024
Morse–Kelley set theory (category Systems of set theory)
z\in y.} Identical to Extensionality above. I would be identical to the axiom of extensionality in ZFC, except that the scope of I includes proper classes...
21 KB (3,186 words) - 12:28, 4 February 2025
an axiom is a premise or starting point for reasoning. In mathematics, an axiom may be a "logical axiom" or a "non-logical axiom". Logical axioms are...
34 KB (4,918 words) - 17:20, 18 June 2025
capture the notion of the extension of anything is the idea behind the axiom of extensionality in axiomatic set theory. This kind of extension is used so constantly...
6 KB (773 words) - 22:53, 6 January 2025
mathematics, the axiom of choice, abbreviated AC or AoC, is an axiom of set theory. Informally put, the axiom of choice says that given any collection of non-empty...
60 KB (7,931 words) - 03:30, 22 June 2025
satisfy the axiom of extensionality. A set further is hereditarily ordinal definable if it is ordinal definable and all elements of its transitive closure...
3 KB (441 words) - 23:10, 9 March 2024
Russell's paradox (redirect from List of all lists which do not contain themselves)
non-logical predicate ∈ {\displaystyle \in } , and that includes the axiom of extensionality: ∀ x ∀ y ( ∀ z ( z ∈ x ⟺ z ∈ y ) ⟹ x = y ) {\displaystyle \forall...
32 KB (4,621 words) - 14:05, 26 May 2025