Department of Mathematics, University of Science and Technology of China, Hefei, Anhui 230026, PR China
Abstract:
In this paper, we corrected some errors in [J. Geom. Phys. 40 (2002) 370]. In [J. Geom. Phys. 40 (2002) 370], the errors in Eqs. (32) and (44) influenced the conclusion of Theorem 3.1, Corollary 3.1 and Theorem 3.2.