Metamath Proof Explorer


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 ( 𝜑 → ( 𝜓𝜒 ) )
Assertion pm4.71da ( 𝜑 → ( 𝜓 ↔ ( 𝜓𝜒 ) ) )

Proof

Step Hyp Ref Expression
1 pm4.71da.1 ( 𝜑 → ( 𝜓𝜒 ) )
2 1 biimpd ( 𝜑 → ( 𝜓𝜒 ) )
3 2 pm4.71d ( 𝜑 → ( 𝜓 ↔ ( 𝜓𝜒 ) ) )