“…Other cases have different coefficients, like Tr (λ 2 λ 1 λ 3 Λ β ), and should not be computed as they made no contribution to the desired vertex. Because of the fact that we need some of the coefficients a n,m and b n,m , let us address some of them as [6,60] a 0,0 = − π 2 6 , b 0,0 = − π 2 12 , a 1,0 = 2ζ(3), a 0,1 = 0, b 0,1 = −ζ(3), a 1,1 = a 0,2 = −7π 4 /90,…”