Metamath Proof Explorer


Theorem 3ancomb

Description: Commutation law for triple conjunction. (Contributed by NM, 21-Apr-1994) (Revised to shorten 3anrot by Wolf Lammen, 9-Jun-2022.)

Ref Expression
Assertion 3ancomb φ ψ χ φ χ ψ

Proof

Step Hyp Ref Expression
1 df-3an φ ψ χ φ ψ χ
2 3anan32 φ χ ψ φ ψ χ
3 1 2 bitr4i φ ψ χ φ χ ψ