Description: Inference similar to Theorem 19.23 of Margaris p. 90. (Contributed by Alan Sare, 21-Apr-2013) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | exlimexi.1 | |- ( ps -> A. x ps ) |
|
exlimexi.2 | |- ( E. x ph -> ( ph -> ps ) ) |
||
Assertion | exlimexi | |- ( E. x ph -> ps ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | exlimexi.1 | |- ( ps -> A. x ps ) |
|
2 | exlimexi.2 | |- ( E. x ph -> ( ph -> ps ) ) |
|
3 | hbe1 | |- ( E. x ph -> A. x E. x ph ) |
|
4 | 3 1 2 | exlimdh | |- ( E. x ph -> ( E. x ph -> ps ) ) |
5 | 4 | pm2.43i | |- ( E. x ph -> ps ) |