Ryszard Urbański i Jerzy GrzybowskiShadowing set and finite exhausters
We will introduce the notation of a shadowing set, which is a generalization of the notion of separating set to the family of more than two sets. We will prove some theorems dealing with the shadowing set. Furthermore, we will give the criterion for upper exhauster to be an exhauster of sublinear function as well as the criterion for minimality of finite upper exhauster. All the results will be illustrated by examples.