Theorem pm4.71da

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 ) ) )

Proof

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 ) ) )