fact: Definition FinSubset_ball (e:Q) (x:X) (l:list X) : Prop := ~~ exists y:X, In y l /\ ball e x y.
imports: CoRN.model.totalorder.QposMinMax CoRN.metric2.Hausdorff CoRN.logic.Classic CoRN.stdlib_omissions.List CoRN.metric2.Classification CoRN.metric2.Complete CoRN.metric2.Prelength