Metamath Proof Explorer


Theorem pm5.32ri

Description: Distribution of implication over biconditional (inference form). (Contributed by NM, 12-Mar-1995)

Ref Expression
Hypothesis pm5.32i.1 ( 𝜑 → ( 𝜓𝜒 ) )
Assertion pm5.32ri ( ( 𝜓𝜑 ) ↔ ( 𝜒𝜑 ) )

Proof

Step Hyp Ref Expression
1 pm5.32i.1 ( 𝜑 → ( 𝜓𝜒 ) )
2 1 pm5.32i ( ( 𝜑𝜓 ) ↔ ( 𝜑𝜒 ) )
3 ancom ( ( 𝜓𝜑 ) ↔ ( 𝜑𝜓 ) )
4 ancom ( ( 𝜒𝜑 ) ↔ ( 𝜑𝜒 ) )
5 2 3 4 3bitr4i ( ( 𝜓𝜑 ) ↔ ( 𝜒𝜑 ) )