Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012) (Proof shortened by Wolf Lammen, 23-Jun-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | simpll1 | |- ( ( ( ( ph /\ ps /\ ch ) /\ th ) /\ ta ) -> ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simp1 | |- ( ( ph /\ ps /\ ch ) -> ph ) |
|
| 2 | 1 | ad2antrr | |- ( ( ( ( ph /\ ps /\ ch ) /\ th ) /\ ta ) -> ph ) |