proposition: Lemma ler_wnM2r x : x <= 0 -> {homo *%R^~ x : y z /~ y <= z}.
proof: Proof. by move=> x_le0 y z leyz; rewrite -![_ * x]mulrNN ler_wpM2r ?lterNE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)