proposition: Lemma ltr_distlCBl x y e : `|x - y| < e -> y - e < x.
proof: Proof. exact: real_ltr_distlCBl. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)