Description: Restricted specialization, using implicit substitution. (Contributed by Mario Carneiro, 4-Jan-2017) Avoid ax-10 and ax-11 . (Revised by GG, 20-Aug-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | spcimdv.1 | |- ( ph -> A e. B ) |
|
| spcimdv.2 | |- ( ( ph /\ x = A ) -> ( ps -> ch ) ) |
||
| Assertion | spcimdv | |- ( ph -> ( A. x ps -> ch ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | spcimdv.1 | |- ( ph -> A e. B ) |
|
| 2 | spcimdv.2 | |- ( ( ph /\ x = A ) -> ( ps -> ch ) ) |
|
| 3 | elisset | |- ( A e. B -> E. x x = A ) |
|
| 4 | 1 3 | syl | |- ( ph -> E. x x = A ) |
| 5 | 2 | ex | |- ( ph -> ( x = A -> ( ps -> ch ) ) ) |
| 6 | 5 | eximdv | |- ( ph -> ( E. x x = A -> E. x ( ps -> ch ) ) ) |
| 7 | 4 6 | mpd | |- ( ph -> E. x ( ps -> ch ) ) |
| 8 | 19.36v | |- ( E. x ( ps -> ch ) <-> ( A. x ps -> ch ) ) |
|
| 9 | 7 8 | sylib | |- ( ph -> ( A. x ps -> ch ) ) |