Actions that characterize \(l_\infty^{(n)}\) (Q1377505)

It is a classical result of Nachbin that if the identity operator on an \(n\)-dimensional Banach space \(V\) can be extended to any Banach space with the same norm, then \(V\) is isometric to \(\ell^{(n)}_\infty\). In this work, the authors show that the identity is the only linear operator with this property.