proposition: Lemma nbhs_left_ge x z : z < x -> \forall y \near x^'-, z <= y.
proof: Proof. by move=> xz; near do apply/ltW; apply: nbhs_left_gt. Unshelve. all: by end_near. 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