Description: Simplification of triple conjunction. (Contributed by NM, 21-Apr-1994) (Proof shortened by Andrew Salmon, 13-May-2011) (Proof shortened by Wolf Lammen, 21-Jun-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3simpc | |- ( ( ph /\ ps /\ ch ) -> ( ps /\ ch ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | id | |- ( ( ps /\ ch ) -> ( ps /\ ch ) ) |
|
| 2 | 1 | 3adant1 | |- ( ( ph /\ ps /\ ch ) -> ( ps /\ ch ) ) |