proposition: Lemma ler_eXz2l x (x1 : 1 < x) : {mono exprz x : x y / x <= y}.
proof: Proof. apply: (le_mono (inj_homo_lt _ _)). by apply: ieexprIz; rewrite ?(lt_trans ltr01) // gt_eqF. by apply: ler_weXz2l; rewrite ?ltW. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)