Description: Uniqueness inferred from existential uniqueness. (Contributed by NM, 5-Apr-1995)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | eumoi.1 | ⊢ ∃! 𝑥 𝜑 | |
| Assertion | eumoi | ⊢ ∃* 𝑥 𝜑 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eumoi.1 | ⊢ ∃! 𝑥 𝜑 | |
| 2 | eumo | ⊢ ( ∃! 𝑥 𝜑 → ∃* 𝑥 𝜑 ) | |
| 3 | 1 2 | ax-mp | ⊢ ∃* 𝑥 𝜑 |