Theorem cbvabdavw 36825

Description: Change bound variable in class abstractions. Deduction form. (Contributed by GG, 14-Aug-2025.)

Hypothesis

Ref	Expression
cbvabdavw.1	⊢ ((𝜑 ∧ 𝑥 = 𝑦) → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
cbvabdavw	⊢ (𝜑 → {𝑥 ∣ 𝜓} = {𝑦 ∣ 𝜒})

Distinct variable groups:   𝜑,𝑥,𝑦   𝜓,𝑦   𝜒,𝑥

Allowed substitution hints:   𝜓(𝑥)   𝜒(𝑦)

Proof of Theorem cbvabdavw

Dummy variable 𝑡 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		cbvabdavw.1	. . . 4 ⊢ ((𝜑 ∧ 𝑥 = 𝑦) → (𝜓 ↔ 𝜒))
2	1	cbvsbdavw 36823	. . 3 ⊢ (𝜑 → ([𝑡 / 𝑥]𝜓 ↔ [𝑡 / 𝑦]𝜒))
3		df-clab 2744	. . 3 ⊢ (𝑡 ∈ {𝑥 ∣ 𝜓} ↔ [𝑡 / 𝑥]𝜓)
4		df-clab 2744	. . 3 ⊢ (𝑡 ∈ {𝑦 ∣ 𝜒} ↔ [𝑡 / 𝑦]𝜒)
5	2, 3, 4	3bitr4g 317	. 2 ⊢ (𝜑 → (𝑡 ∈ {𝑥 ∣ 𝜓} ↔ 𝑡 ∈ {𝑦 ∣ 𝜒}))
6	5	eqrdv 2763	1 ⊢ (𝜑 → {𝑥 ∣ 𝜓} = {𝑦 ∣ 𝜒})

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   = wceq 1570  [wsb 2099   ∈ wcel 2146  {cab 2743

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-9 2156  ax-ext 2737

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-sb 2100  df-clab 2744  df-cleq 2757

This theorem is used by:  cbvsbcdavw  36826  cbvsbcdavw2  36827  cbvrabdavw  36830  cbviotadavw  36838  cbvixpdavw  36847  cbvrabdavw2  36854  cbvixpdavw2  36863