Theorem vtoclgft 3540

Description: Closed theorem form of vtoclgf 3554. The reverse implication is proven in ceqsal1t 3504. See ceqsalt 3505 for a version with 𝑥 and 𝐴 disjoint. (Contributed by NM, 17-Feb-2013.) (Revised by Mario Carneiro, 12-Oct-2016.) (Proof shortened by JJ, 11-Aug-2021.) Avoid ax-13 2371. (Revised by Gino Giotto, 6-Oct-2023.)

Assertion

Ref	Expression
vtoclgft	⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → 𝜓)

Proof of Theorem vtoclgft

Dummy variable 𝑧 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		elissetv 2814	. . . . 5 ⊢ (𝐴 ∈ 𝑉 → ∃𝑧 𝑧 = 𝐴)
2		nfv 1917	. . . . . . . 8 ⊢ Ⅎ𝑧Ⅎ𝑥𝐴
3		nfnfc1 2906	. . . . . . . 8 ⊢ Ⅎ𝑥Ⅎ𝑥𝐴
4		nfcvd 2904	. . . . . . . . . 10 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥𝑧)
5		id 22	. . . . . . . . . 10 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥𝐴)
6	4, 5	nfeqd 2913	. . . . . . . . 9 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥 𝑧 = 𝐴)
7	6	nfnd 1861	. . . . . . . 8 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥 ¬ 𝑧 = 𝐴)
8		nfvd 1918	. . . . . . . 8 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑧 ¬ 𝑥 = 𝐴)
9		eqeq1 2736	. . . . . . . . . 10 ⊢ (𝑧 = 𝑥 → (𝑧 = 𝐴 ↔ 𝑥 = 𝐴))
10	9	notbid 317	. . . . . . . . 9 ⊢ (𝑧 = 𝑥 → (¬ 𝑧 = 𝐴 ↔ ¬ 𝑥 = 𝐴))
11	10	a1i 11	. . . . . . . 8 ⊢ (Ⅎ𝑥𝐴 → (𝑧 = 𝑥 → (¬ 𝑧 = 𝐴 ↔ ¬ 𝑥 = 𝐴)))
12	2, 3, 7, 8, 11	cbv2w 2333	. . . . . . 7 ⊢ (Ⅎ𝑥𝐴 → (∀𝑧 ¬ 𝑧 = 𝐴 ↔ ∀𝑥 ¬ 𝑥 = 𝐴))
13		alnex 1783	. . . . . . 7 ⊢ (∀𝑧 ¬ 𝑧 = 𝐴 ↔ ¬ ∃𝑧 𝑧 = 𝐴)
14		alnex 1783	. . . . . . 7 ⊢ (∀𝑥 ¬ 𝑥 = 𝐴 ↔ ¬ ∃𝑥 𝑥 = 𝐴)
15	12, 13, 14	3bitr3g 312	. . . . . 6 ⊢ (Ⅎ𝑥𝐴 → (¬ ∃𝑧 𝑧 = 𝐴 ↔ ¬ ∃𝑥 𝑥 = 𝐴))
16	15	con4bid 316	. . . . 5 ⊢ (Ⅎ𝑥𝐴 → (∃𝑧 𝑧 = 𝐴 ↔ ∃𝑥 𝑥 = 𝐴))
17	1, 16	imbitrid 243	. . . 4 ⊢ (Ⅎ𝑥𝐴 → (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 = 𝐴))
18	17	ad2antrr 724	. . 3 ⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑)) → (𝐴 ∈ 𝑉 → ∃𝑥 𝑥 = 𝐴))
19	18	3impia 1117	. 2 ⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → ∃𝑥 𝑥 = 𝐴)
20		biimp 214	. . . . . . . . 9 ⊢ ((𝜑 ↔ 𝜓) → (𝜑 → 𝜓))
21	20	imim2i 16	. . . . . . . 8 ⊢ ((𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) → (𝑥 = 𝐴 → (𝜑 → 𝜓)))
22	21	com23 86	. . . . . . 7 ⊢ ((𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) → (𝜑 → (𝑥 = 𝐴 → 𝜓)))
23	22	imp 407	. . . . . 6 ⊢ (((𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ 𝜑) → (𝑥 = 𝐴 → 𝜓))
24	23	alanimi 1818	. . . . 5 ⊢ ((∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) → ∀𝑥(𝑥 = 𝐴 → 𝜓))
25		19.23t 2203	. . . . . 6 ⊢ (Ⅎ𝑥𝜓 → (∀𝑥(𝑥 = 𝐴 → 𝜓) ↔ (∃𝑥 𝑥 = 𝐴 → 𝜓)))
26	25	adantl 482	. . . . 5 ⊢ ((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) → (∀𝑥(𝑥 = 𝐴 → 𝜓) ↔ (∃𝑥 𝑥 = 𝐴 → 𝜓)))
27	24, 26	imbitrid 243	. . . 4 ⊢ ((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) → ((∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) → (∃𝑥 𝑥 = 𝐴 → 𝜓)))
28	27	imp 407	. . 3 ⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑)) → (∃𝑥 𝑥 = 𝐴 → 𝜓))
29	28	3adant3 1132	. 2 ⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → (∃𝑥 𝑥 = 𝐴 → 𝜓))
30	19, 29	mpd 15	1 ⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜓) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜑 ↔ 𝜓)) ∧ ∀𝑥𝜑) ∧ 𝐴 ∈ 𝑉) → 𝜓)

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205   ∧ wa 396   ∧ w3a 1087  ∀wal 1539   = wceq 1541  ∃wex 1781  Ⅎwnf 1785   ∈ wcel 2106  Ⅎwnfc 2883

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-11 2154  ax-12 2171  ax-ext 2703

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 846  df-3an 1089  df-ex 1782  df-nf 1786  df-cleq 2724  df-clel 2810  df-nfc 2885

This theorem is referenced by:  vtocldf  3541  bj-vtoclgfALT  35935