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
|- ( ( ph /\ x = y ) -> ( ps <-> ch ) )
cbvrabdavw2.2
|- ( ( ph /\ x = y ) -> A = B )
Assertion cbvrabdavw2
|- ( ph -> { x e. A | ps } = { y e. B | ch } )

Proof

Step Hyp Ref Expression
1 cbvrabdavw2.1
 |-  ( ( ph /\ x = y ) -> ( ps <-> ch ) )
2 cbvrabdavw2.2
 |-  ( ( ph /\ x = y ) -> A = B )
3 eleq1w
 |-  ( x = y -> ( x e. A <-> y e. A ) )
4 3 adantl
 |-  ( ( ph /\ x = y ) -> ( x e. A <-> y e. A ) )
5 2 eleq2d
 |-  ( ( ph /\ x = y ) -> ( y e. A <-> y e. B ) )
6 4 5 bitrd
 |-  ( ( ph /\ x = y ) -> ( x e. A <-> y e. B ) )
7 6 1 anbi12d
 |-  ( ( ph /\ x = y ) -> ( ( x e. A /\ ps ) <-> ( y e. B /\ ch ) ) )
8 7 cbvabdavw
 |-  ( ph -> { x | ( x e. A /\ ps ) } = { y | ( y e. B /\ ch ) } )
9 df-rab
 |-  { x e. A | ps } = { x | ( x e. A /\ ps ) }
10 df-rab
 |-  { y e. B | ch } = { y | ( y e. B /\ ch ) }
11 8 9 10 3eqtr4g
 |-  ( ph -> { x e. A | ps } = { y e. B | ch } )