Metamath Proof Explorer

Theorem exim

Description: Theorem 19.22 of Margaris p. 90. (Contributed by NM, 10-Jan-1993) (Proof shortened by Wolf Lammen, 4-Jul-2014)

Ref Expression
Assertion exim 
|- ( A. x ( ph -> ps ) -> ( E. x ph -> E. x ps ) )

Proof

Step Hyp Ref Expression
1 id 
 |-  ( ( ph -> ps ) -> ( ph -> ps ) )
2 1 aleximi 
 |-  ( A. x ( ph -> ps ) -> ( E. x ph -> E. x ps ) )