Description: Prove a restricted existential. (Contributed by Rohan Ridenour, 3-Aug-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rspcime.1 | |- ( ( ph /\ x = A ) -> ps ) |
|
| rspcime.2 | |- ( ph -> A e. B ) |
||
| Assertion | rspcime | |- ( ph -> E. x e. B ps ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rspcime.1 | |- ( ( ph /\ x = A ) -> ps ) |
|
| 2 | rspcime.2 | |- ( ph -> A e. B ) |
|
| 3 | simpl | |- ( ( ph /\ x = A ) -> ph ) |
|
| 4 | 1 3 | 2thd | |- ( ( ph /\ x = A ) -> ( ps <-> ph ) ) |
| 5 | id | |- ( ph -> ph ) |
|
| 6 | 2 4 5 | rspcedvd | |- ( ph -> E. x e. B ps ) |