proposition: Lemma cvg_ex (T : nbhsType) (F : set_system T) : cvg F <-> (exists l : T, F --> l).
proof: Proof. exact: cvg_in_ex. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed