proposition: Lemma divpN p q : (- p) %/ q = - (p %/ q).
proof: Proof. by apply/eqP; rewrite -addr_eq0 -divpD addNr div0p. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop ssralg poly)