Metamath Proof Explorer


Theorem 3imp231

Description: Importation inference. (Contributed by Alan Sare, 17-Oct-2017)

Ref Expression
Hypothesis 3imp.1 φ ψ χ θ
Assertion 3imp231 ψ χ φ θ

Proof

Step Hyp Ref Expression
1 3imp.1 φ ψ χ θ
2 1 com3l ψ χ φ θ
3 2 3imp ψ χ φ θ