Description: Simplification of triple conjunction. (Contributed by NM, 9-Nov-2011)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simp2l | |- ( ( ph /\ ( ps /\ ch ) /\ th ) -> ps ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simpl | |- ( ( ps /\ ch ) -> ps ) | |
| 2 | 1 | 3ad2ant2 | |- ( ( ph /\ ( ps /\ ch ) /\ th ) -> ps ) |