Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012) (Proof shortened by Wolf Lammen, 23-Jun-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | simpl1l | |- ( ( ( ( ph /\ ps ) /\ ch /\ th ) /\ ta ) -> ph ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpll | |- ( ( ( ph /\ ps ) /\ ta ) -> ph ) |
|
2 | 1 | 3ad2antl1 | |- ( ( ( ( ph /\ ps ) /\ ch /\ th ) /\ ta ) -> ph ) |