proposition: Lemma nbhs_open_ereal_pinfty r : (nbhs +oo [set y | r%:E < y])%E.
proof: Proof. rewrite nbhsE /=; eexists; last by move=> y; exact. by split; [apply open_ereal_gt_ereal | rewrite /= ltry]. 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