proposition: Lemma subset_closed_ball (R : realFieldType) (V : pseudoMetricType R) (x : V) (r : R) : ball x r `<=` closed_ball x r.
proof: Proof. exact: subset_closure. 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