proposition: Lemma nbhs_ball_norm (x : V) (eps : {posnum R}) : nbhs x (ball_norm x eps%:num).
proof: Proof. rewrite -nbhs_nbhs_norm; apply: nbhs_norm_ball_norm. 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