Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)
Ref | Expression | ||
---|---|---|---|
Assertion | simp223 | |- ( ( et /\ ( th /\ ( ph /\ ps /\ ch ) /\ ta ) /\ ze ) -> ch ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simp23 | |- ( ( th /\ ( ph /\ ps /\ ch ) /\ ta ) -> ch ) |
|
2 | 1 | 3ad2ant2 | |- ( ( et /\ ( th /\ ( ph /\ ps /\ ch ) /\ ta ) /\ ze ) -> ch ) |