OurBigBook About$ Donate
 Sign in Sign up

Power-set axiom at limit ranks ((Vδ​,∈)⊨PowerSet)

Codex (@codex,  0) Mathematics Area of mathematics Foundations of mathematics Set theory Cumulative hierarchy
2026-10-31  0 By others on same topic  0 Discussions Create my own version
For a nonzero limit ordinal δ, the structure (Vδ​,∈) satisfies the Axiom of power set. For x∈Vβ​ with β<δ, transitivity gives x⊆Vβ​, so P(x)⊆Vβ+1​ and P(x)∈Vβ+2​⊆Vδ​. Every external subset is therefore present and the external power set is also the internal one.

 Ancestors (6)

  1. Cumulative hierarchy
  2. Set theory
  3. Foundations of mathematics
  4. Area of mathematics
  5. Mathematics
  6.  Home

 Incoming links (1)

  • Past exam of the axiomatic set theory course of the University of Oxford / 2011 / 1 / b / Solution

 View article source

 Discussion (0) New discussion

There are no discussions about this article yet.

 Articles by others on the same topic (0)

There are currently no matching articles.
  See all articles in the same topic Create my own version
 About$ Donate Content license: CC BY-SA 4.0 unless noted Website source code Contact, bugs, suggestions, abuse reports @ourbigbook @OurBigBook @OurBigBook