Finite dimensional approximations for functional differential equations with input and output delays

The authors present some results on the numerical approximations for linear retarded functional differential equations with delays in control and observation. Specifically, they consider the averaging approximation scheme for such systems treated as evolution equations with unbounded input and output operators in the state space set-up developed by A.J. Pritchard and D. Salamon (Technical Report no.2624, Mathematics Research Center, University of Wisconsin, Madison, WI, 1984).<>