proposition: Lemma strong_monoN p a r : strong_mono p a r -> strong_mono (- p) a r.
proof: Proof. by case=> [] hp; [right; apply: accr_negN|left; apply: accr_posN]. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(bigop order ssralg ssrnum ssrint rat poly polydiv polyorder) mathcomp(perm matrix mxpoly polyXY binomial bigenough)