Theorem acnrcl 9943

Description: Reverse closure for the choice set predicate. (Contributed by Mario Carneiro, 31-Aug-2015.)

Assertion

Ref	Expression
acnrcl	⊢ (𝑋 ∈ AC 𝐴 → 𝐴 ∈ V)

Proof of Theorem acnrcl

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

Step	Hyp	Ref	Expression
1		ne0i 4292	. . 3 ⊢ (𝑋 ∈ {𝑥 ∣ (𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦))} → {𝑥 ∣ (𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦))} ≠ ∅)
2		abn0 4336	. . . 4 ⊢ ({𝑥 ∣ (𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦))} ≠ ∅ ↔ ∃𝑥(𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦)))
3		simpl 482	. . . . 5 ⊢ ((𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦)) → 𝐴 ∈ V)
4	3	exlimiv 1931	. . . 4 ⊢ (∃𝑥(𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦)) → 𝐴 ∈ V)
5	2, 4	sylbi 217	. . 3 ⊢ ({𝑥 ∣ (𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦))} ≠ ∅ → 𝐴 ∈ V)
6	1, 5	syl 17	. 2 ⊢ (𝑋 ∈ {𝑥 ∣ (𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦))} → 𝐴 ∈ V)
7		df-acn 9845	. 2 ⊢ AC 𝐴 = {𝑥 ∣ (𝐴 ∈ V ∧ ∀𝑓 ∈ ((𝒫 𝑥 ∖ {∅}) ↑m 𝐴)∃𝑔∀𝑦 ∈ 𝐴 (𝑔‘𝑦) ∈ (𝑓‘𝑦))}
8	6, 7	eleq2s 2851	1 ⊢ (𝑋 ∈ AC 𝐴 → 𝐴 ∈ V)

Syntax hints:   → wi 4   ∧ wa 395  ∃wex 1780   ∈ wcel 2113  {cab 2711   ≠ wne 2930  ∀wral 3049  Vcvv 3438   ∖ cdif 3896  ∅c0 4284  𝒫 cpw 4551  {csn 4577  ‘cfv 6489  (class class class)co 7355   ↑_m cmap 8759  AC wacn 9841

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-10 2146  ax-11 2162  ax-12 2182  ax-ext 2705

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-tru 1544  df-fal 1554  df-ex 1781  df-nf 1785  df-sb 2068  df-clab 2712  df-cleq 2725  df-clel 2808  df-ne 2931  df-dif 3902  df-nul 4285  df-acn 9845

This theorem is referenced by:  acni  9946  acni2  9947  acndom2  9955  fodomacn  9957  iundom2g  10441