Metamath Proof Explorer


Theorem euop2

Description: Transfer existential uniqueness to second member of an ordered pair. (Contributed by NM, 10-Apr-2004)

Ref Expression
Hypothesis euop2.1 A V
Assertion euop2 ∃! x y x = A y φ ∃! y φ

Proof

Step Hyp Ref Expression
1 euop2.1 A V
2 opex A y V
3 1 moop2 * y x = A y
4 2 3 euxfr2w ∃! x y x = A y φ ∃! y φ