Theorem vtocl3 2675

Description: Implicit substitution of classes for setvar variables. (Contributed by NM, 3-Jun-1995.) (Proof shortened by Andrew Salmon, 8-Jun-2011.)

Hypotheses

Ref	Expression
vtocl3.1	⊢ 𝐴 ∈ V
vtocl3.2	⊢ 𝐵 ∈ V
vtocl3.3	⊢ 𝐶 ∈ V
vtocl3.4	⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) → (𝜑 ↔ 𝜓))
vtocl3.5	⊢ 𝜑

Assertion

Ref	Expression
vtocl3	⊢ 𝜓

Distinct variable groups:   𝑥,𝑦,𝑧,𝐴   𝑥,𝐵,𝑦,𝑧   𝑥,𝐶,𝑦,𝑧   𝜓,𝑥,𝑦,𝑧

Allowed substitution hints:   𝜑(𝑥,𝑦,𝑧)

Proof of Theorem vtocl3

Step	Hyp	Ref	Expression
1		vtocl3.1	. . . . . . 7 ⊢ 𝐴 ∈ V
2	1	isseti 2627	. . . . . 6 ⊢ ∃𝑥 𝑥 = 𝐴
3		vtocl3.2	. . . . . . 7 ⊢ 𝐵 ∈ V
4	3	isseti 2627	. . . . . 6 ⊢ ∃𝑦 𝑦 = 𝐵
5		vtocl3.3	. . . . . . 7 ⊢ 𝐶 ∈ V
6	5	isseti 2627	. . . . . 6 ⊢ ∃𝑧 𝑧 = 𝐶
7		eeeanv 1856	. . . . . . 7 ⊢ (∃𝑥∃𝑦∃𝑧(𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) ↔ (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵 ∧ ∃𝑧 𝑧 = 𝐶))
8		vtocl3.4	. . . . . . . . . 10 ⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) → (𝜑 ↔ 𝜓))
9	8	biimpd 142	. . . . . . . . 9 ⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) → (𝜑 → 𝜓))
10	9	eximi 1536	. . . . . . . 8 ⊢ (∃𝑧(𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) → ∃𝑧(𝜑 → 𝜓))
11	10	2eximi 1537	. . . . . . 7 ⊢ (∃𝑥∃𝑦∃𝑧(𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) → ∃𝑥∃𝑦∃𝑧(𝜑 → 𝜓))
12	7, 11	sylbir 133	. . . . . 6 ⊢ ((∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵 ∧ ∃𝑧 𝑧 = 𝐶) → ∃𝑥∃𝑦∃𝑧(𝜑 → 𝜓))
13	2, 4, 6, 12	mp3an 1273	. . . . 5 ⊢ ∃𝑥∃𝑦∃𝑧(𝜑 → 𝜓)
14		nfv 1466	. . . . . . 7 ⊢ Ⅎ𝑧𝜓
15	14	19.36-1 1608	. . . . . 6 ⊢ (∃𝑧(𝜑 → 𝜓) → (∀𝑧𝜑 → 𝜓))
16	15	2eximi 1537	. . . . 5 ⊢ (∃𝑥∃𝑦∃𝑧(𝜑 → 𝜓) → ∃𝑥∃𝑦(∀𝑧𝜑 → 𝜓))
17	13, 16	ax-mp 7	. . . 4 ⊢ ∃𝑥∃𝑦(∀𝑧𝜑 → 𝜓)
18		nfv 1466	. . . . 5 ⊢ Ⅎ𝑦𝜓
19	18	19.36-1 1608	. . . 4 ⊢ (∃𝑦(∀𝑧𝜑 → 𝜓) → (∀𝑦∀𝑧𝜑 → 𝜓))
20	17, 19	eximii 1538	. . 3 ⊢ ∃𝑥(∀𝑦∀𝑧𝜑 → 𝜓)
21	20	19.36aiv 1829	. 2 ⊢ (∀𝑥∀𝑦∀𝑧𝜑 → 𝜓)
22		vtocl3.5	. . 3 ⊢ 𝜑
23	22	gen2 1384	. 2 ⊢ ∀𝑦∀𝑧𝜑
24	21, 23	mpg 1385	1 ⊢ 𝜓

Syntax hints:   → wi 4   ↔ wb 103   ∧ w3a 924  ∀wal 1287   = wceq 1289  ∃wex 1426   ∈ wcel 1438  Vcvv 2619

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1381  ax-7 1382  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-8 1440  ax-4 1445  ax-17 1464  ax-i9 1468  ax-ial 1472  ax-ext 2070

This theorem depends on definitions:  df-bi 115  df-3an 926  df-nf 1395  df-sb 1693  df-clab 2075  df-cleq 2081  df-clel 2084  df-v 2621

This theorem is referenced by: (None)