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 } ) |