Theorem pwex 3932

Description: Power set axiom expressed in class notation. Axiom 4 of [TakeutiZaring] p. 17. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 25-Jul-2011.)

Hypothesis

Ref	Expression
zfpowcl.1	⊢ 𝐴 ∈ V

Assertion

Ref	Expression
pwex	⊢ 𝒫 𝐴 ∈ V

Proof of Theorem pwex

Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		zfpowcl.1	. 2 ⊢ 𝐴 ∈ V
2		pweq 3362	. . 3 ⊢ (𝑧 = 𝐴 → 𝒫 𝑧 = 𝒫 𝐴)
3	2	eleq1d 2106	. 2 ⊢ (𝑧 = 𝐴 → (𝒫 𝑧 ∈ V ↔ 𝒫 𝐴 ∈ V))
4		df-pw 3361	. . 3 ⊢ 𝒫 𝑧 = {𝑦 ∣ 𝑦 ⊆ 𝑧}
5		axpow2 3929	. . . . . 6 ⊢ ∃𝑥∀𝑦(𝑦 ⊆ 𝑧 → 𝑦 ∈ 𝑥)
6	5	bm1.3ii 3878	. . . . 5 ⊢ ∃𝑥∀𝑦(𝑦 ∈ 𝑥 ↔ 𝑦 ⊆ 𝑧)
7		abeq2 2146	. . . . . 6 ⊢ (𝑥 = {𝑦 ∣ 𝑦 ⊆ 𝑧} ↔ ∀𝑦(𝑦 ∈ 𝑥 ↔ 𝑦 ⊆ 𝑧))
8	7	exbii 1496	. . . . 5 ⊢ (∃𝑥 𝑥 = {𝑦 ∣ 𝑦 ⊆ 𝑧} ↔ ∃𝑥∀𝑦(𝑦 ∈ 𝑥 ↔ 𝑦 ⊆ 𝑧))
9	6, 8	mpbir 134	. . . 4 ⊢ ∃𝑥 𝑥 = {𝑦 ∣ 𝑦 ⊆ 𝑧}
10	9	issetri 2564	. . 3 ⊢ {𝑦 ∣ 𝑦 ⊆ 𝑧} ∈ V
11	4, 10	eqeltri 2110	. 2 ⊢ 𝒫 𝑧 ∈ V
12	1, 3, 11	vtocl 2608	1 ⊢ 𝒫 𝐴 ∈ V

Syntax hints:   ↔ wb 98  ∀wal 1241   = wceq 1243  ∃wex 1381   ∈ wcel 1393  {cab 2026  Vcvv 2557   ⊆ wss 2917  𝒫 cpw 3359

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-11 1397  ax-4 1400  ax-14 1405  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022  ax-sep 3875  ax-pow 3927

This theorem depends on definitions:  df-bi 110  df-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-v 2559  df-in 2924  df-ss 2931  df-pw 3361

This theorem is referenced by:  pwexg  3933  p0ex  3939  pp0ex  3940  ord3ex  3941  abexssex  5752  npex  6571  axcnex  6935  pnfxr  8692  mnfxr  8694  ixxex  8768