fact: Definition NearBy (l : X) (ε : QposInf) := ForAll (λ s, ball_ex ε (hd s) l).
imports: CoRN.algebra.RSetoid CoRN.model.totalorder.QposMinMax Coq.QArith.QArith Coq.Bool.Bool CoRN.metric2.Complete MathClasses.theory.CoqStreams MathClasses.interfaces.abstract_algebra MathClasses.theory.streams MathClasses.orders.naturals