Metamath Proof Explorer


Theorem reximi

Description: Inference quantifying both antecedent and consequent. (Contributed by NM, 18-Oct-1996)

Ref Expression
Hypothesis reximi.1
|- ( ph -> ps )
Assertion reximi
|- ( E. x e. A ph -> E. x e. A ps )

Proof

Step Hyp Ref Expression
1 reximi.1
 |-  ( ph -> ps )
2 1 a1i
 |-  ( x e. A -> ( ph -> ps ) )
3 2 reximia
 |-  ( E. x e. A ph -> E. x e. A ps )