proposition: Lemma nbhs_left_lt x : \forall y \near x^'-, y < x.
proof: Proof. by rewrite near_withinE; apply: nearW. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrint ssrnum finmap matrix) mathcomp(rat interval zmodp vector fieldext falgebra) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality set_interval Rstruct) ereal reals signed topology prodnormedzmodule