proposition: Lemma mul0rn n : 0 *+ n = 0 :> V.
proof: Proof. by elim: n => // n IHn; rewrite mulrS add0r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)