proposition: Lemma cvg_ball {T} {F} {FF : Filter F} (f : T -> M) y : f @ F --> y -> forall eps : R, 0 < eps -> \forall x \near F, ball y eps (f x).
proof: Proof. exact: fcvg_ball. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed