proposition: Lemma drop_poly0l p : drop_poly 0 p = p.
proof: Proof. by apply/polyP => i; rewrite coef_poly subn0 addn0 if_nth ?leqVgt. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)