Two Generalizations of Property (II) and their characterization

Abstract: The concept of Property (II) was introduced and characterized by Chen and Lin \cite{CL}. In this work, given a compatiable collection of bounded sets $\mathcal{A}$, we provide a complete characterization of two generalizations of Property (II) : (i) every closed convex set $A\in \mathcal{A}$ is an intersection of closed convex hulls of finitely many balls and (ii) for every closed convex set $A\in \mathcal{A}$ and $\beta \geqslant 0$, $\overline{A+\beta B_X}$ is an intersection of closed convex hulls of finitely many balls.