Metamath Proof Explorer


Theorem pm5.74i

Description: Distribution of implication over biconditional (inference form). (Contributed by NM, 1-Aug-1994)

Ref Expression
Hypothesis pm5.74i.1 ( 𝜑 → ( 𝜓𝜒 ) )
Assertion pm5.74i ( ( 𝜑𝜓 ) ↔ ( 𝜑𝜒 ) )

Proof

Step Hyp Ref Expression
1 pm5.74i.1 ( 𝜑 → ( 𝜓𝜒 ) )
2 pm5.74 ( ( 𝜑 → ( 𝜓𝜒 ) ) ↔ ( ( 𝜑𝜓 ) ↔ ( 𝜑𝜒 ) ) )
3 1 2 mpbi ( ( 𝜑𝜓 ) ↔ ( 𝜑𝜒 ) )