Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simp2r3 | |- ( ( ta /\ ( th /\ ( ph /\ ps /\ ch ) ) /\ et ) -> ch ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simpr3 | |- ( ( th /\ ( ph /\ ps /\ ch ) ) -> ch ) | |
| 2 | 1 | 3ad2ant2 | |- ( ( ta /\ ( th /\ ( ph /\ ps /\ ch ) ) /\ et ) -> ch ) |