Metamath Proof Explorer


Theorem eumoi

Description: Uniqueness inferred from existential uniqueness. (Contributed by NM, 5-Apr-1995)

Ref Expression
Hypothesis eumoi.1 ∃!xφ
Assertion eumoi *xφ

Proof

Step Hyp Ref Expression
1 eumoi.1 ∃!xφ
2 eumo ∃!xφ*xφ
3 1 2 ax-mp *xφ