Theorem vtocl3 3530

Description: Implicit substitution of classes for setvar variables. (Contributed by NM, 3-Jun-1995.) (Proof shortened by Andrew Salmon, 8-Jun-2011.) Avoid ax-10 2178 and ax-11 2194. (Revised by GG, 20-Aug-2023.) (Proof shortened by Wolf Lammen, 23-Aug-2023.)

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,𝐴   𝑥,𝑦,𝐵   𝑥,𝑧,𝐶,𝑦   𝜓,𝑥,𝑦,𝑧

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

Proof of Theorem vtocl3

Step	Hyp	Ref	Expression
1		vtocl3.3	. 2 ⊢ 𝐶 ∈ V
2		vtocl3.1	. . 3 ⊢ 𝐴 ∈ V
3		vtocl3.2	. . 3 ⊢ 𝐵 ∈ V
4		vtocl3.4	. . . . 5 ⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵 ∧ 𝑧 = 𝐶) → (𝜑 ↔ 𝜓))
5	4	3expa 1136	. . . 4 ⊢ (((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ 𝑧 = 𝐶) → (𝜑 ↔ 𝜓))
6	5	pm5.74da 816	. . 3 ⊢ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) → ((𝑧 = 𝐶 → 𝜑) ↔ (𝑧 = 𝐶 → 𝜓)))
7		vtocl3.5	. . . 4 ⊢ 𝜑
8	7	a1i 11	. . 3 ⊢ (𝑧 = 𝐶 → 𝜑)
9	2, 3, 6, 8	vtocl2 3529	. 2 ⊢ (𝑧 = 𝐶 → 𝜓)
10	1, 9	vtocle 3521	1 ⊢ 𝜓

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   ∧ w3a 1103   = wceq 1570   ∈ wcel 2145  Vcvv 3453

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147

This proof depends on definitions:  df-bi 210  df-an 402  df-3an 1105  df-ex 1813  df-clel 2837

This theorem is used by: (None)