Metamath Proof Explorer


Theorem biimpac

Description: Importation inference from a logical equivalence. (Contributed by NM, 3-May-1994)

Ref Expression
Hypothesis biimpa.1 ( 𝜑 → ( 𝜓𝜒 ) )
Assertion biimpac ( ( 𝜓𝜑 ) → 𝜒 )

Proof

Step Hyp Ref Expression
1 biimpa.1 ( 𝜑 → ( 𝜓𝜒 ) )
2 1 biimpcd ( 𝜓 → ( 𝜑𝜒 ) )
3 2 imp ( ( 𝜓𝜑 ) → 𝜒 )