Theorem vtocldf 2823

Description: Implicit substitution of a class for a setvar variable. (Contributed by Mario Carneiro, 15-Oct-2016.)

Hypotheses

Ref	Expression
vtocld.1	⊢ (𝜑 → 𝐴 ∈ 𝑉)
vtocld.2	⊢ ((𝜑 ∧ 𝑥 = 𝐴) → (𝜓 ↔ 𝜒))
vtocld.3	⊢ (𝜑 → 𝜓)
vtocldf.4	⊢ Ⅎ𝑥𝜑
vtocldf.5	⊢ (𝜑 → Ⅎ𝑥𝐴)
vtocldf.6	⊢ (𝜑 → Ⅎ𝑥𝜒)

Assertion

Ref	Expression
vtocldf	⊢ (𝜑 → 𝜒)

Proof of Theorem vtocldf

Step	Hyp	Ref	Expression
1		vtocldf.5	. 2 ⊢ (𝜑 → Ⅎ𝑥𝐴)
2		vtocldf.6	. 2 ⊢ (𝜑 → Ⅎ𝑥𝜒)
3		vtocldf.4	. . 3 ⊢ Ⅎ𝑥𝜑
4		vtocld.2	. . . 4 ⊢ ((𝜑 ∧ 𝑥 = 𝐴) → (𝜓 ↔ 𝜒))
5	4	ex 115	. . 3 ⊢ (𝜑 → (𝑥 = 𝐴 → (𝜓 ↔ 𝜒)))
6	3, 5	alrimi 1544	. 2 ⊢ (𝜑 → ∀𝑥(𝑥 = 𝐴 → (𝜓 ↔ 𝜒)))
7		vtocld.3	. . 3 ⊢ (𝜑 → 𝜓)
8	3, 7	alrimi 1544	. 2 ⊢ (𝜑 → ∀𝑥𝜓)
9		vtocld.1	. 2 ⊢ (𝜑 → 𝐴 ∈ 𝑉)
10		vtoclgft 2822	. 2 ⊢ (((Ⅎ𝑥𝐴 ∧ Ⅎ𝑥𝜒) ∧ (∀𝑥(𝑥 = 𝐴 → (𝜓 ↔ 𝜒)) ∧ ∀𝑥𝜓) ∧ 𝐴 ∈ 𝑉) → 𝜒)
11	1, 2, 6, 8, 9, 10	syl221anc 1260	1 ⊢ (𝜑 → 𝜒)

Syntax hints:   → wi 4   ∧ wa 104   ↔ wb 105  ∀wal 1370   = wceq 1372  Ⅎwnf 1482   ∈ wcel 2175  Ⅎwnfc 2334

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1469  ax-7 1470  ax-gen 1471  ax-ie1 1515  ax-ie2 1516  ax-8 1526  ax-4 1532  ax-17 1548  ax-i9 1552  ax-ial 1556  ax-i5r 1557  ax-ext 2186

This theorem depends on definitions:  df-bi 117  df-3an 982  df-nf 1483  df-sb 1785  df-clab 2191  df-cleq 2197  df-clel 2200  df-nfc 2336  df-v 2773

This theorem is referenced by:  vtocld  2824  peano2  4642  iota2df  5256