Metamath Proof Explorer


Theorem bj-wnfanf

Description: When ph is substituted for ps , this statement expresses that weak nonfreeness implies the universal form of nonfreeness. (Contributed by BJ, 9-Dec-2023)

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

Proof

Step Hyp Ref Expression
1 bj-wnf1
 |-  ( ( E. x ph -> A. x ps ) -> A. x ( E. x ph -> A. x ps ) )
2 bj-19.23bit
 |-  ( ( E. x ph -> A. x ps ) -> ( ph -> A. x ps ) )
3 1 2 sylg
 |-  ( ( E. x ph -> A. x ps ) -> A. x ( ph -> A. x ps ) )