Description: Express that an intersection is not empty. (Contributed by RP, 16-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0pssin | |- ( (/) C. ( A i^i B ) <-> E. x ( x e. A /\ x e. B ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0pss | |- ( (/) C. ( A i^i B ) <-> ( A i^i B ) =/= (/) ) |
|
| 2 | ndisj | |- ( ( A i^i B ) =/= (/) <-> E. x ( x e. A /\ x e. B ) ) |
|
| 3 | 1 2 | bitri | |- ( (/) C. ( A i^i B ) <-> E. x ( x e. A /\ x e. B ) ) |