fact: Definition nat_plus_perm201 : ∏ n0 n1 n2, n0 + n1 + n2 = n1 + n2 + n0 := λ n0 n1 n2, pathscomp0 (natplusassoc n0 n1 n2) (natpluscomm n0 (n1 + n2)).
imports: UniMath.Foundations.NaturalNumbers UniMath.Tactics.Utilities UniMath.Tactics.Abmonoids_Tactics