Description: Equivalent wff's yield equal restricted class abstractions. (Contributed by Glauco Siliprandi, 23-Oct-2021)
Ref | Expression | ||
---|---|---|---|
Hypotheses | rabbida2.1 | |- F/ x ph |
|
rabbida2.2 | |- ( ph -> A = B ) |
||
rabbida2.3 | |- ( ph -> ( ps <-> ch ) ) |
||
Assertion | rabbida2 | |- ( ph -> { x e. A | ps } = { x e. B | ch } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rabbida2.1 | |- F/ x ph |
|
2 | rabbida2.2 | |- ( ph -> A = B ) |
|
3 | rabbida2.3 | |- ( ph -> ( ps <-> ch ) ) |
|
4 | 2 | eleq2d | |- ( ph -> ( x e. A <-> x e. B ) ) |
5 | 4 3 | anbi12d | |- ( ph -> ( ( x e. A /\ ps ) <-> ( x e. B /\ ch ) ) ) |
6 | 1 5 | abbid | |- ( ph -> { x | ( x e. A /\ ps ) } = { x | ( x e. B /\ ch ) } ) |
7 | df-rab | |- { x e. A | ps } = { x | ( x e. A /\ ps ) } |
|
8 | df-rab | |- { x e. B | ch } = { x | ( x e. B /\ ch ) } |
|
9 | 6 7 8 | 3eqtr4g | |- ( ph -> { x e. A | ps } = { x e. B | ch } ) |