Some Remarks about an Identifiability Result of Nonlinear Systems

The aim of this paper is to give an example that shows the bad use of Corollary 2 (Vajda et al., 1989, p. 233) in various applications (Chappell et al., 1990; Chappell and Godfrey, 1992) in order to prove identifiability results in uncontrolled systems.