Comment on “A constructive proof on the existence of globally exponentially attractive set and positive invariant set of general Lorenz family”, P. Yu, X.X. Liao, S.L. Xie, Y.L. Fu [Commun Nonlinear Sci Numer Simulat 14 (2009) 2886-2896]
Keywords: General Lorenz family; Globally exponentially attractive set; Positive invariant set; Generalized Lyapunov function; Ultimate boundness of chaotic system;