proposition: Lemma real_ltr_distlBl x y e : x - y \is real -> `|x - y| < e -> x - e < y.
proof: Proof. by move/real_ltr_distlDr; rewrite ltrBlDr; apply. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)