Reply to comments on ‘Sufficient conditions for the synthesis of H∞ fixed‐order controllers’

In this brief note Theorems 1 and 2 (Int. J. Robust Nonlinear Control 2000; 10:1237–1242) are discussed in the light of the observations raised in Feng and Allen (Int. J. Robust Nonlinear Control). A simple correction to the proof of these theorems allows to keep the hypothesis on the possible rank deficiency of the system matrices B and Cy. Copyright © 2004 John Wiley & Sons, Ltd.