A note on Kharitonov-type results in the space of Markov parameters

C.V. Hollot (ibid., vol.34, no.5, p.536-May 1989) used Markov´s theorem of determinants to obtain the largest stability box around a nominal Hurtwitz polynomial under coefficient perturbation, in the space of Markov´s parameters. In the present work, the authors use some previously established related research results to considerably simplify the proposed technique, and make it computationally more efficient. These results are also extended to the discrete-time case and some illustrative examples are given