Metamath Proof Explorer


Theorem com3l

Description: Commutation of antecedents. Rotate left. (Contributed by NM, 25-Apr-1994) (Proof shortened by Wolf Lammen, 28-Jul-2012)

Ref Expression
Hypothesis com3.1 ⊢ φ → ψ → χ → θ
Assertion com3l ⊢ ψ → χ → φ → θ

Proof

Step Hyp Ref Expression
1 com3.1 ⊢ φ → ψ → χ → θ
2 1 com3r ⊢ χ → φ → ψ → θ
3 2 com3r ⊢ ψ → χ → φ → θ