Cascade control of systems over integral domains (Q797519)

This short paper presents a straight forward generalization of the results of \textit{A. S. Morse} [Lect. Notes Econ. Math. Syst. 131, 61-74 (1976; Zbl 0343.93031) and \textit{W. A. Wolovich} and \textit{P. L. Falb} [J. Control Optimization 14, 996-1008 (1976; Zbl 0344.93015)] about the existence of cascade compensators transforming a given proper rational transfer matrix into another one. The results are extended to systems over arbitrary integral domains D, but since in this case it makes no difference to analyse the problem over the field of fractions K instead of D, the extended results are hardly surprising.