proposition: Lemma mul0R x : 0 * x == 0.
proof: Proof. by apply (@addRI (0 * x)); rewrite -mulRDl !addR0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div order) mathcomp(ssralg ssrnum ssrint rat intdiv) Coq(Morphisms Setoid) fourcolor(real realsyntax)