Metamath Proof Explorer


Theorem 3ancoma

Description: Commutation law for triple conjunction. (Contributed by NM, 21-Apr-1994) (Proof shortened by Wolf Lammen, 5-Jun-2022)

Ref Expression
Assertion 3ancoma φ ψ χ ψ φ χ

Proof

Step Hyp Ref Expression
1 3anan12 φ ψ χ ψ φ χ
2 3anass ψ φ χ ψ φ χ
3 1 2 bitr4i φ ψ χ ψ φ χ