Metamath Proof Explorer


Theorem bj-rcleqf

Description: Relative version of cleqf . (Contributed by BJ, 27-Dec-2023)

Ref Expression
Hypotheses bj-rcleqf.a
|- F/_ x A
bj-rcleqf.b
|- F/_ x B
bj-rcleqf.v
|- F/_ x V
Assertion bj-rcleqf
|- ( ( V i^i A ) = ( V i^i B ) <-> A. x e. V ( x e. A <-> x e. B ) )

Proof

Step Hyp Ref Expression
1 bj-rcleqf.a
 |-  F/_ x A
2 bj-rcleqf.b
 |-  F/_ x B
3 bj-rcleqf.v
 |-  F/_ x V
4 elin
 |-  ( x e. ( V i^i A ) <-> ( x e. V /\ x e. A ) )
5 elin
 |-  ( x e. ( V i^i B ) <-> ( x e. V /\ x e. B ) )
6 4 5 bibi12i
 |-  ( ( x e. ( V i^i A ) <-> x e. ( V i^i B ) ) <-> ( ( x e. V /\ x e. A ) <-> ( x e. V /\ x e. B ) ) )
7 pm5.32
 |-  ( ( x e. V -> ( x e. A <-> x e. B ) ) <-> ( ( x e. V /\ x e. A ) <-> ( x e. V /\ x e. B ) ) )
8 6 7 bitr4i
 |-  ( ( x e. ( V i^i A ) <-> x e. ( V i^i B ) ) <-> ( x e. V -> ( x e. A <-> x e. B ) ) )
9 8 albii
 |-  ( A. x ( x e. ( V i^i A ) <-> x e. ( V i^i B ) ) <-> A. x ( x e. V -> ( x e. A <-> x e. B ) ) )
10 3 1 nfin
 |-  F/_ x ( V i^i A )
11 3 2 nfin
 |-  F/_ x ( V i^i B )
12 10 11 cleqf
 |-  ( ( V i^i A ) = ( V i^i B ) <-> A. x ( x e. ( V i^i A ) <-> x e. ( V i^i B ) ) )
13 df-ral
 |-  ( A. x e. V ( x e. A <-> x e. B ) <-> A. x ( x e. V -> ( x e. A <-> x e. B ) ) )
14 9 12 13 3bitr4i
 |-  ( ( V i^i A ) = ( V i^i B ) <-> A. x e. V ( x e. A <-> x e. B ) )