Metamath Proof Explorer


Theorem r19.37

Description: Restricted quantifier version of one direction of 19.37 . (The other direction does not hold when A is empty.) (Contributed by FL, 13-May-2012) (Revised by Mario Carneiro, 11-Dec-2016)

Ref Expression
Hypothesis r19.37.1
|- F/ x ph
Assertion r19.37
|- ( E. x e. A ( ph -> ps ) -> ( ph -> E. x e. A ps ) )

Proof

Step Hyp Ref Expression
1 r19.37.1
 |-  F/ x ph
2 r19.35
 |-  ( E. x e. A ( ph -> ps ) <-> ( A. x e. A ph -> E. x e. A ps ) )
3 ax-1
 |-  ( ph -> ( x e. A -> ph ) )
4 1 3 ralrimi
 |-  ( ph -> A. x e. A ph )
5 4 imim1i
 |-  ( ( A. x e. A ph -> E. x e. A ps ) -> ( ph -> E. x e. A ps ) )
6 2 5 sylbi
 |-  ( E. x e. A ( ph -> ps ) -> ( ph -> E. x e. A ps ) )