Metamath Proof Explorer


Theorem 2reureurex

Description: Double restricted existential uniqueness implies restricted existential uniqueness with restricted existence. (Contributed by AV, 5-Jul-2023)

Ref Expression
Assertion 2reureurex
|- ( E! x e. A , y e. B ph -> E! x e. A E. y e. B ph )

Proof

Step Hyp Ref Expression
1 df-2reu
 |-  ( E! x e. A , y e. B ph <-> ( E! x e. A E. y e. B ph /\ E! y e. B E. x e. A ph ) )
2 1 simplbi
 |-  ( E! x e. A , y e. B ph -> E! x e. A E. y e. B ph )