  - This article deals with the derivation of ISS-Lyapunov functions for
infinite-dimensional linear systems subject to saturations. Two cases are
considered: 1) the saturation acts in the same space as the control space; 2)
the saturation acts in another space, especially a Banach space. For the first
case, an explicit ISS-Lyapunov function can be derived. For the second case, we
can only ensure the existence of an ISS-Lyapunov function.
