Metamath Proof Explorer


Theorem cbvrabdavw2

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

Ref Expression
Hypotheses cbvrabdavw2.1 ( ( 𝜑𝑥 = 𝑦 ) → ( 𝜓𝜒 ) )
cbvrabdavw2.2 ( ( 𝜑𝑥 = 𝑦 ) → 𝐴 = 𝐵 )
Assertion cbvrabdavw2 ( 𝜑 → { 𝑥𝐴𝜓 } = { 𝑦𝐵𝜒 } )

Proof

Step Hyp Ref Expression
1 cbvrabdavw2.1 ( ( 𝜑𝑥 = 𝑦 ) → ( 𝜓𝜒 ) )
2 cbvrabdavw2.2 ( ( 𝜑𝑥 = 𝑦 ) → 𝐴 = 𝐵 )
3 eleq1w ( 𝑥 = 𝑦 → ( 𝑥𝐴𝑦𝐴 ) )
4 3 adantl ( ( 𝜑𝑥 = 𝑦 ) → ( 𝑥𝐴𝑦𝐴 ) )
5 2 eleq2d ( ( 𝜑𝑥 = 𝑦 ) → ( 𝑦𝐴𝑦𝐵 ) )
6 4 5 bitrd ( ( 𝜑𝑥 = 𝑦 ) → ( 𝑥𝐴𝑦𝐵 ) )
7 6 1 anbi12d ( ( 𝜑𝑥 = 𝑦 ) → ( ( 𝑥𝐴𝜓 ) ↔ ( 𝑦𝐵𝜒 ) ) )
8 7 cbvabdavw ( 𝜑 → { 𝑥 ∣ ( 𝑥𝐴𝜓 ) } = { 𝑦 ∣ ( 𝑦𝐵𝜒 ) } )
9 df-rab { 𝑥𝐴𝜓 } = { 𝑥 ∣ ( 𝑥𝐴𝜓 ) }
10 df-rab { 𝑦𝐵𝜒 } = { 𝑦 ∣ ( 𝑦𝐵𝜒 ) }
11 8 9 10 3eqtr4g ( 𝜑 → { 𝑥𝐴𝜓 } = { 𝑦𝐵𝜒 } )