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 ) |