Description: Existential elimination rule of natural deduction (Rule C, explained in exlimiv ). (Contributed by Mario Carneiro, 15-Jun-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | exlimddv.1 | |- ( ph -> E. x ps ) |
|
| exlimddv.2 | |- ( ( ph /\ ps ) -> ch ) |
||
| Assertion | exlimddv | |- ( ph -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | exlimddv.1 | |- ( ph -> E. x ps ) |
|
| 2 | exlimddv.2 | |- ( ( ph /\ ps ) -> ch ) |
|
| 3 | 2 | ex | |- ( ph -> ( ps -> ch ) ) |
| 4 | 3 | exlimdv | |- ( ph -> ( E. x ps -> ch ) ) |
| 5 | 1 4 | mpd | |- ( ph -> ch ) |