Metamath Proof Explorer
Description: Inference form of Theorem 19.23 of Margaris p. 90, see 19.23 .
(Contributed by NM, 12-Mar-1993)
|
|
Ref |
Expression |
|
Hypothesis |
19.23bi.1 |
|- ( E. x ph -> ps ) |
|
Assertion |
19.23bi |
|- ( ph -> ps ) |
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
19.23bi.1 |
|- ( E. x ph -> ps ) |
| 2 |
|
19.8a |
|- ( ph -> E. x ph ) |
| 3 |
2 1
|
syl |
|- ( ph -> ps ) |