Description: Closed form of nexdv . (Contributed by BJ, 20-Oct-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-nexdvt | |- ( A. x ( ph -> -. ps ) -> ( ph -> -. E. x ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfv | |- F/ x ph |
|
2 | bj-nexdt | |- ( F/ x ph -> ( A. x ( ph -> -. ps ) -> ( ph -> -. E. x ps ) ) ) |
|
3 | 1 2 | ax-mp | |- ( A. x ( ph -> -. ps ) -> ( ph -> -. E. x ps ) ) |