proposition: Lemma real_ltr_normlP x y : x \is real -> reflect ((-x < y) * (x < y)) (`|x| < y).
proof: Proof. by move=> Rx; rewrite real_ltr_norml // ltrNl; apply: (iffP (@andP _ _)); case. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)