Description: Equality theorem for restricted class abstractions. Inference form of rabeqf . (Contributed by Glauco Siliprandi, 26-Jun-2021) Avoid ax-10 , ax-11 , ax-12 . (Revised by Gino Giotto, 3-Jun-2024)
Ref | Expression | ||
---|---|---|---|
Hypothesis | rabeqi.1 | |- A = B |
|
Assertion | rabeqi | |- { x e. A | ph } = { x e. B | ph } |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rabeqi.1 | |- A = B |
|
2 | 1 | eleq2i | |- ( x e. A <-> x e. B ) |
3 | 2 | anbi1i | |- ( ( x e. A /\ ph ) <-> ( x e. B /\ ph ) ) |
4 | 3 | rabbia2 | |- { x e. A | ph } = { x e. B | ph } |