Metamath Proof Explorer


Theorem cbvraldva2

Description: Rule used to change the bound variable in a restricted universal quantifier with implicit substitution which also changes the quantifier domain. Deduction form. (Contributed by David Moews, 1-May-2017)

Ref Expression
Hypotheses cbvraldva2.1
|- ( ( ph /\ x = y ) -> ( ps <-> ch ) )
cbvraldva2.2
|- ( ( ph /\ x = y ) -> A = B )
Assertion cbvraldva2
|- ( ph -> ( A. x e. A ps <-> A. y e. B ch ) )

Proof

Step Hyp Ref Expression
1 cbvraldva2.1
 |-  ( ( ph /\ x = y ) -> ( ps <-> ch ) )
2 cbvraldva2.2
 |-  ( ( ph /\ x = y ) -> A = B )
3 simpr
 |-  ( ( ph /\ x = y ) -> x = y )
4 3 2 eleq12d
 |-  ( ( ph /\ x = y ) -> ( x e. A <-> y e. B ) )
5 4 1 imbi12d
 |-  ( ( ph /\ x = y ) -> ( ( x e. A -> ps ) <-> ( y e. B -> ch ) ) )
6 5 cbvaldvaw
 |-  ( ph -> ( A. x ( x e. A -> ps ) <-> A. y ( y e. B -> ch ) ) )
7 df-ral
 |-  ( A. x e. A ps <-> A. x ( x e. A -> ps ) )
8 df-ral
 |-  ( A. y e. B ch <-> A. y ( y e. B -> ch ) )
9 6 7 8 3bitr4g
 |-  ( ph -> ( A. x e. A ps <-> A. y e. B ch ) )