Description: Existential uniqueness implies uniqueness. (Contributed by NM, 23-Mar-1995)
Ref | Expression | ||
---|---|---|---|
Assertion | eumo | ⊢ ( ∃! 𝑥 𝜑 → ∃* 𝑥 𝜑 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-eu | ⊢ ( ∃! 𝑥 𝜑 ↔ ( ∃ 𝑥 𝜑 ∧ ∃* 𝑥 𝜑 ) ) | |
2 | 1 | simprbi | ⊢ ( ∃! 𝑥 𝜑 → ∃* 𝑥 𝜑 ) |