proposition: Lemma dvdC_mul2l x y z : y != 0 -> (y * x %| y * z)%C = (x %| z)%C.
proof: Proof. by rewrite !(mulrC y); apply: dvdC_mul2r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun ssrnat eqtype seq choice) mathcomp(div fintype path bigop finset prime order ssralg) mathcomp(poly polydiv mxpoly generic_quotient countalg) mathcomp(ssrnum closed_field ssrint archimedean rat intdiv) mathcomp(algebraics_fundamentals)