References . S. Weinberg, Infrared photons and gravitons , Phys. Rev.140 (1965) B516 [ INSPIRE ]. Z. Bern et al., The Duality Between Color and Kinematics and its Applications , arXiv:1909.01358 [ INSPIRE ]. P. Benincasa and F. Cachazo, Consistency Conditions on the S-Matrix of Massless Particles , arXiv:0705.4305 [ INSPIRE ]. P.C. Schuster and N. Toro, Constructing the Tree-Level Yang-Mills S-Matrix Using Complex Factorization , JHEP06 (2009...