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 |