Description: Restricted existential specialization, using implicit substitution. Variant of rspcedv . (Contributed by AV, 27-Nov-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rspcedvd.1 | |- ( ph -> A e. B ) |
|
| rspcedvd.2 | |- ( ( ph /\ x = A ) -> ( ps <-> ch ) ) |
||
| rspcedvd.3 | |- ( ph -> ch ) |
||
| Assertion | rspcedvd | |- ( ph -> E. x e. B ps ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rspcedvd.1 | |- ( ph -> A e. B ) |
|
| 2 | rspcedvd.2 | |- ( ( ph /\ x = A ) -> ( ps <-> ch ) ) |
|
| 3 | rspcedvd.3 | |- ( ph -> ch ) |
|
| 4 | 1 2 | rspcedv | |- ( ph -> ( ch -> E. x e. B ps ) ) |
| 5 | 3 4 | mpd | |- ( ph -> E. x e. B ps ) |