Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simp213 | |- ( ( et /\ ( ( ph /\ ps /\ ch ) /\ th /\ ta ) /\ ze ) -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simp13 | |- ( ( ( ph /\ ps /\ ch ) /\ th /\ ta ) -> ch ) |
|
| 2 | 1 | 3ad2ant2 | |- ( ( et /\ ( ( ph /\ ps /\ ch ) /\ th /\ ta ) /\ ze ) -> ch ) |