Metamath Proof Explorer


Theorem ralbidb

Description: Formula-building rule for restricted universal quantifier and additional condition (deduction form). See ralbidc for a more generalized form. (Contributed by Zhi Wang, 6-Sep-2024)

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

Proof

Step Hyp Ref Expression
1 ralbidb.1
 |-  ( ph -> ( x e. A <-> ( x e. B /\ ps ) ) )
2 ralbidb.2
 |-  ( ( ph /\ x e. A ) -> ( ch <-> th ) )
3 1 2 logic1a
 |-  ( ph -> ( ( x e. A -> ch ) <-> ( ( x e. B /\ ps ) -> th ) ) )
4 impexp
 |-  ( ( ( x e. B /\ ps ) -> th ) <-> ( x e. B -> ( ps -> th ) ) )
5 3 4 bitrdi
 |-  ( ph -> ( ( x e. A -> ch ) <-> ( x e. B -> ( ps -> th ) ) ) )
6 5 ralbidv2
 |-  ( ph -> ( A. x e. A ch <-> A. x e. B ( ps -> th ) ) )