Theorem vtocl2gf 2835

Description: Implicit substitution of a class for a setvar variable. (Contributed by NM, 25-Apr-1995.)

Hypotheses

Ref	Expression
vtocl2gf.1	⊢ Ⅎ𝑥𝐴
vtocl2gf.2	⊢ Ⅎ𝑦𝐴
vtocl2gf.3	⊢ Ⅎ𝑦𝐵
vtocl2gf.4	⊢ Ⅎ𝑥𝜓
vtocl2gf.5	⊢ Ⅎ𝑦𝜒
vtocl2gf.6	⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓))
vtocl2gf.7	⊢ (𝑦 = 𝐵 → (𝜓 ↔ 𝜒))
vtocl2gf.8	⊢ 𝜑

Assertion

Ref	Expression
vtocl2gf	⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 𝜒)

Proof of Theorem vtocl2gf

Step	Hyp	Ref	Expression
1		elex 2783	. 2 ⊢ (𝐴 ∈ 𝑉 → 𝐴 ∈ V)
2		vtocl2gf.3	. . 3 ⊢ Ⅎ𝑦𝐵
3		vtocl2gf.2	. . . . 5 ⊢ Ⅎ𝑦𝐴
4	3	nfel1 2359	. . . 4 ⊢ Ⅎ𝑦 𝐴 ∈ V
5		vtocl2gf.5	. . . 4 ⊢ Ⅎ𝑦𝜒
6	4, 5	nfim 1595	. . 3 ⊢ Ⅎ𝑦(𝐴 ∈ V → 𝜒)
7		vtocl2gf.7	. . . 4 ⊢ (𝑦 = 𝐵 → (𝜓 ↔ 𝜒))
8	7	imbi2d 230	. . 3 ⊢ (𝑦 = 𝐵 → ((𝐴 ∈ V → 𝜓) ↔ (𝐴 ∈ V → 𝜒)))
9		vtocl2gf.1	. . . 4 ⊢ Ⅎ𝑥𝐴
10		vtocl2gf.4	. . . 4 ⊢ Ⅎ𝑥𝜓
11		vtocl2gf.6	. . . 4 ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓))
12		vtocl2gf.8	. . . 4 ⊢ 𝜑
13	9, 10, 11, 12	vtoclgf 2831	. . 3 ⊢ (𝐴 ∈ V → 𝜓)
14	2, 6, 8, 13	vtoclgf 2831	. 2 ⊢ (𝐵 ∈ 𝑊 → (𝐴 ∈ V → 𝜒))
15	1, 14	mpan9 281	1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 𝜒)

Syntax hints:   → wi 4   ∧ wa 104   ↔ wb 105   = wceq 1373  Ⅎwnf 1483   ∈ wcel 2176  Ⅎwnfc 2335  Vcvv 2772

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-io 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-v 2774

This theorem is referenced by:  vtocl3gf  2836  vtocl2g  2837  vtocl2gaf  2840