Description: Deduction adding a conjunct to antecedent. (Contributed by NM, 4-May-1994) (Proof shortened by Wolf Lammen, 24-Nov-2012)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | adant2.1 | |- ( ( ph /\ ps ) -> ch ) |
|
| Assertion | adantll | |- ( ( ( th /\ ph ) /\ ps ) -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | adant2.1 | |- ( ( ph /\ ps ) -> ch ) |
|
| 2 | simpr | |- ( ( th /\ ph ) -> ph ) |
|
| 3 | 2 1 | sylan | |- ( ( ( th /\ ph ) /\ ps ) -> ch ) |