Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simp121 | |- ( ( ( th /\ ( ph /\ ps /\ ch ) /\ ta ) /\ et /\ ze ) -> ph )  | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simp21 | |- ( ( th /\ ( ph /\ ps /\ ch ) /\ ta ) -> ph )  | 
						|
| 2 | 1 | 3ad2ant1 | |- ( ( ( th /\ ( ph /\ ps /\ ch ) /\ ta ) /\ et /\ ze ) -> ph )  |