Metamath Proof Explorer


Theorem biimpac

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

Ref Expression
Hypothesis biimpa.1 ⊢ φ → ψ ↔ χ
Assertion biimpac ⊢ ψ ∧ φ → χ

Proof

Step Hyp Ref Expression
1 biimpa.1 ⊢ φ → ψ ↔ χ
2 1 biimpcd ⊢ ψ → φ → χ
3 2 imp ⊢ ψ ∧ φ → χ