Metamath Proof Explorer


Theorem pm5.32rd

Description: Distribution of implication over biconditional (deduction form). (Contributed by NM, 25-Dec-2004)

Ref Expression
Hypothesis pm5.32d.1 ( 𝜑 → ( 𝜓 → ( 𝜒𝜃 ) ) )
Assertion pm5.32rd ( 𝜑 → ( ( 𝜒𝜓 ) ↔ ( 𝜃𝜓 ) ) )

Proof

Step Hyp Ref Expression
1 pm5.32d.1 ( 𝜑 → ( 𝜓 → ( 𝜒𝜃 ) ) )
2 1 pm5.32d ( 𝜑 → ( ( 𝜓𝜒 ) ↔ ( 𝜓𝜃 ) ) )
3 ancom ( ( 𝜒𝜓 ) ↔ ( 𝜓𝜒 ) )
4 ancom ( ( 𝜃𝜓 ) ↔ ( 𝜓𝜃 ) )
5 2 3 4 3bitr4g ( 𝜑 → ( ( 𝜒𝜓 ) ↔ ( 𝜃𝜓 ) ) )