Reply to 'Conjugate points and optimal control; counterexamples'

The author asserts that the so-called counterexamples given by V. Zeidan and P. Zerra (ibid., pp. 254-255, Feb 1989) pertaining to the necessary controllability assumptions are at best remarks that these assumptions were not originally explicit enough. He argues that the original presentation did not explicitly summarize these conditions because they were clear from the context of the presentation.