Metamath Proof Explorer


Theorem eumo

Description: Existential uniqueness implies uniqueness. (Contributed by NM, 23-Mar-1995)

Ref Expression
Assertion eumo ( ∃! 𝑥 𝜑 → ∃* 𝑥 𝜑 )

Proof

Step Hyp Ref Expression
1 df-eu ( ∃! 𝑥 𝜑 ↔ ( ∃ 𝑥 𝜑 ∧ ∃* 𝑥 𝜑 ) )
2 1 simprbi ( ∃! 𝑥 𝜑 → ∃* 𝑥 𝜑 )