Metamath Proof Explorer


Theorem exp12bd

Description: The import-export theorem ( impexp ) for biconditionals (deduction form). (Contributed by Zhi Wang, 3-Sep-2024)

Ref Expression
Hypothesis exp12bd.1 ( 𝜑 → ( ( ( 𝜓𝜒 ) → 𝜃 ) ↔ ( ( 𝜏𝜂 ) → 𝜁 ) ) )
Assertion exp12bd ( 𝜑 → ( ( 𝜓 → ( 𝜒𝜃 ) ) ↔ ( 𝜏 → ( 𝜂𝜁 ) ) ) )

Proof

Step Hyp Ref Expression
1 exp12bd.1 ( 𝜑 → ( ( ( 𝜓𝜒 ) → 𝜃 ) ↔ ( ( 𝜏𝜂 ) → 𝜁 ) ) )
2 impexp ( ( ( 𝜓𝜒 ) → 𝜃 ) ↔ ( 𝜓 → ( 𝜒𝜃 ) ) )
3 impexp ( ( ( 𝜏𝜂 ) → 𝜁 ) ↔ ( 𝜏 → ( 𝜂𝜁 ) ) )
4 1 2 3 3bitr3g ( 𝜑 → ( ( 𝜓 → ( 𝜒𝜃 ) ) ↔ ( 𝜏 → ( 𝜂𝜁 ) ) ) )