proposition: Lemma divp_addl_mul_small q r : size r < size d -> (q * d + r) %/ d = q.
proof: Proof. by move=> srd; rewrite divpD (divp_small srd) addr0 mulpK. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop ssralg poly)