Description: Equivalent wff's yield equal restricted class abstractions. (Contributed by Thierry Arnoux, 4-Feb-2017)
Ref | Expression | ||
---|---|---|---|
Hypothesis | rabbidva2.1 | |- ( ph -> ( ( x e. A /\ ps ) <-> ( x e. B /\ ch ) ) ) |
|
Assertion | rabbidva2 | |- ( ph -> { x e. A | ps } = { x e. B | ch } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rabbidva2.1 | |- ( ph -> ( ( x e. A /\ ps ) <-> ( x e. B /\ ch ) ) ) |
|
2 | 1 | abbidv | |- ( ph -> { x | ( x e. A /\ ps ) } = { x | ( x e. B /\ ch ) } ) |
3 | df-rab | |- { x e. A | ps } = { x | ( x e. A /\ ps ) } |
|
4 | df-rab | |- { x e. B | ch } = { x | ( x e. B /\ ch ) } |
|
5 | 2 3 4 | 3eqtr4g | |- ( ph -> { x e. A | ps } = { x e. B | ch } ) |