Correction to "Adaptive NN control for a class of strict-feedback discrete-time nonlinear systems"

The purpose of this note is to correct the typographical errors in Ge, Li, and Lee (2003). According to the definition of ξi f (k), we have ξi (k + n − i + 1) = ηi (k + n − i + 1) + ξi f (k), i = 2, 3, . . . , n, but the terms ηi (k + n − i + 1) are missing. While the main results are unchanged, there should be some consequent modifications in the technical derivations, which are detailed as follows. In Step 1, due to the missing term η2(k+n−1), (A.4) should be updated to