Description: Existential elimination rule of natural deduction. (Contributed by ML, 17-Jul-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | exlimimd.1 | |- ( ph -> E. x ps ) |
|
| exlimimd.2 | |- ( ph -> ( ps -> ch ) ) |
||
| Assertion | exlimimd | |- ( ph -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | exlimimd.1 | |- ( ph -> E. x ps ) |
|
| 2 | exlimimd.2 | |- ( ph -> ( ps -> ch ) ) |
|
| 3 | 2 | imp | |- ( ( ph /\ ps ) -> ch ) |
| 4 | 1 3 | exlimddv | |- ( ph -> ch ) |