This paper provides a complete stability proof of Theorem 1 of the above-mentioned paper(1) for the tracking and the regulation case. In the paper, the proof presented for Theorem 1 only holds for the regulation case where the LaSalle＇s invariant principle may be invoked. In the tracking case, the closed-loop system becomes a nonautonomous one, and arguments other than the LaSalle＇s invariant principle should be used. Here we present these arguments and show that Theorem 1 holds for both cases.