Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012) (Proof shortened by Wolf Lammen, 24-Jun-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simpr1l | |- ( ( ta /\ ( ( ph /\ ps ) /\ ch /\ th ) ) -> ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simprl | |- ( ( ta /\ ( ph /\ ps ) ) -> ph ) |
|
| 2 | 1 | 3ad2antr1 | |- ( ( ta /\ ( ( ph /\ ps ) /\ ch /\ th ) ) -> ph ) |