Description: One direction of 19.37 from the same axioms as 19.37imv . (Contributed by BJ, 2-Dec-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-19.37im | |- ( F// x ph -> ( E. x ( ph -> ps ) -> ( ph -> E. x ps ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 19.35 | |- ( E. x ( ph -> ps ) <-> ( A. x ph -> E. x ps ) ) |
|
2 | bj-nnfa | |- ( F// x ph -> ( ph -> A. x ph ) ) |
|
3 | 2 | imim1d | |- ( F// x ph -> ( ( A. x ph -> E. x ps ) -> ( ph -> E. x ps ) ) ) |
4 | 1 3 | syl5bi | |- ( F// x ph -> ( E. x ( ph -> ps ) -> ( ph -> E. x ps ) ) ) |