proposition: Lemma nbhs_left_neq x : \forall y \near x^'-, y != x.
proof: Proof. by rewrite near_withinE; apply: nearW => ? /lt_eqF->. 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