Comments on “Stabilization of a Fractional-order Chaotic Brushless DC Motor via a Single Input” [Nonlinear Dyn. (2015). DOI 10.1007/s11071-015-2172-4]

Abstract This note shows an incorrect application of the generalized Gronwall inequality for real-valued piecewise continuous functions reported in paper (Zhou et al., 2015). Due to this misleading application, the proof of Theorem 1 and Theorem 2 in Zhou et al., (2015) are incorrect. However, the mentioned Theorem 1 is a conclusion from a combination of some results in later literatures (Zhou et al., 2016 and Wang et al., 2016), and consequently there is no need to prove it. In the same way, although the proof of Theorem 2 in Zhou et al. (2015) is not valid, Theorem 2 is indeed true, and a recommendation as to how to prove it based on Lyapunov candidate function is made to the authors.