proposition: Lemma mulR0 x : x * 0 == 0.
proof: Proof. by rewrite mulRC mul0R. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div order) mathcomp(ssralg ssrnum ssrint rat intdiv) Coq(Morphisms Setoid) fourcolor(real realsyntax)