proposition: Lemma sgz1 : sgz (1 : R) = 1.
proof: Proof. by rewrite gtr0_sgz // ltr01. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)