Description: Deduction converting a biconditional to a biconditional with conjunction. Variant of pm4.71d . (Contributed by Zhi Wang, 30-Aug-2024)
Ref | Expression | ||
---|---|---|---|
Hypothesis | pm4.71da.1 | |- ( ph -> ( ps <-> ch ) ) |
|
Assertion | pm4.71da | |- ( ph -> ( ps <-> ( ps /\ ch ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm4.71da.1 | |- ( ph -> ( ps <-> ch ) ) |
|
2 | 1 | biimpd | |- ( ph -> ( ps -> ch ) ) |
3 | 2 | pm4.71d | |- ( ph -> ( ps <-> ( ps /\ ch ) ) ) |