Description: Two classes that are related by a binary relation are sets. Inference form. (Contributed by BJ, 3-Oct-2022)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | brrelexi.1 | |- Rel R |
|
| Assertion | brrelex12i | |- ( A R B -> ( A e. _V /\ B e. _V ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | brrelexi.1 | |- Rel R |
|
| 2 | brrelex12 | |- ( ( Rel R /\ A R B ) -> ( A e. _V /\ B e. _V ) ) |
|
| 3 | 1 2 | mpan | |- ( A R B -> ( A e. _V /\ B e. _V ) ) |