Metamath Proof Explorer


Theorem bj-gabeqd

Description: Equality of generalized class abstractions. Deduction form. (Contributed by BJ, 4-Oct-2024)

Ref Expression
Hypotheses bj-gabeqd.nf
|- ( ph -> A. x ph )
bj-gabeqd.c
|- ( ph -> A = B )
bj-gabeqd.f
|- ( ph -> ( ps <-> ch ) )
Assertion bj-gabeqd
|- ( ph -> {{ A | x | ps }} = {{ B | x | ch }} )

Proof

Step Hyp Ref Expression
1 bj-gabeqd.nf
 |-  ( ph -> A. x ph )
2 bj-gabeqd.c
 |-  ( ph -> A = B )
3 bj-gabeqd.f
 |-  ( ph -> ( ps <-> ch ) )
4 3 biimpd
 |-  ( ph -> ( ps -> ch ) )
5 1 2 4 bj-gabssd
 |-  ( ph -> {{ A | x | ps }} C_ {{ B | x | ch }} )
6 2 eqcomd
 |-  ( ph -> B = A )
7 3 biimprd
 |-  ( ph -> ( ch -> ps ) )
8 1 6 7 bj-gabssd
 |-  ( ph -> {{ B | x | ch }} C_ {{ A | x | ps }} )
9 5 8 eqssd
 |-  ( ph -> {{ A | x | ps }} = {{ B | x | ch }} )