Description: Restricted unique existence implies restricted existence. (Contributed by NM, 19-Aug-1999)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | reurex | |- ( E! x e. A ph -> E. x e. A ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | reu5 | |- ( E! x e. A ph <-> ( E. x e. A ph /\ E* x e. A ph ) ) |
|
| 2 | 1 | simplbi | |- ( E! x e. A ph -> E. x e. A ph ) |