“…For retarded systems, the spectral abscissa is nonsmooth but continuous in all parameters of the system, including time delays, see [27]. However, it results from [14,2,9,10], that, in general, it is not the case for neutral systems and kernel operators -the so-called associated difference equations, see also [20,21,22]. It is well-known that the spectral abscissa of the difference equation is not continuous in delays.…”