Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simp131 | |- ( ( ( th /\ ta /\ ( ph /\ ps /\ ch ) ) /\ et /\ ze ) -> ph ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simp31 | |- ( ( th /\ ta /\ ( ph /\ ps /\ ch ) ) -> ph ) | |
| 2 | 1 | 3ad2ant1 | |- ( ( ( th /\ ta /\ ( ph /\ ps /\ ch ) ) /\ et /\ ze ) -> ph ) |