Theorem vtoclgOLD 3516

Description: Obsolete version of vtoclg 3515 as of 20-Apr-2024. (Contributed by NM, 17-Apr-1995.) (New usage is discouraged.) (Proof modification is discouraged.)

Hypotheses

Ref	Expression
vtoclgOLD.1	⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓))
vtoclgOLD.2	⊢ 𝜑

Assertion

Ref	Expression
vtoclgOLD	⊢ (𝐴 ∈ 𝑉 → 𝜓)

Distinct variable groups:   𝑥,𝐴   𝜓,𝑥

Allowed substitution hints:   𝜑(𝑥)   𝑉(𝑥)

Proof of Theorem vtoclgOLD

Step	Hyp	Ref	Expression
1		nfv 1915	. 2 ⊢ Ⅎ𝑥𝜓
2		vtoclgOLD.1	. 2 ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓))
3		vtoclgOLD.2	. 2 ⊢ 𝜑
4	1, 2, 3	vtoclg1f 3514	1 ⊢ (𝐴 ∈ 𝑉 → 𝜓)

Syntax hints:   → wi 4   ↔ wb 209   = wceq 1538   ∈ wcel 2111

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 1911  ax-6 1970  ax-7 2015  ax-8 2113  ax-9 2121  ax-12 2175  ax-ext 2770

This theorem depends on definitions:  df-bi 210  df-an 400  df-ex 1782  df-nf 1786  df-cleq 2791  df-clel 2870

This theorem is referenced by: (None)