Description: Deduce a conjunct from a triple conjunction. (Contributed by Jonathan Ben-Naim, 3-Jun-2011)
Ref | Expression | ||
---|---|---|---|
Hypothesis | 3simp1bi.1 | |- ( ph <-> ( ps /\ ch /\ th ) ) |
|
Assertion | simp1bi | |- ( ph -> ps ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 3simp1bi.1 | |- ( ph <-> ( ps /\ ch /\ th ) ) |
|
2 | 1 | biimpi | |- ( ph -> ( ps /\ ch /\ th ) ) |
3 | 2 | simp1d | |- ( ph -> ps ) |