Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012) (Proof shortened by Wolf Lammen, 23-Jun-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simpl3l | |- ( ( ( ch /\ th /\ ( ph /\ ps ) ) /\ ta ) -> ph ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simpll | |- ( ( ( ph /\ ps ) /\ ta ) -> ph ) | |
| 2 | 1 | 3ad2antl3 | |- ( ( ( ch /\ th /\ ( ph /\ ps ) ) /\ ta ) -> ph ) |