In this paper, an error is firstly pointed out in the proof of the main theorems (Theorem 4 and Theorem 6) in [1]. Then the error is corrected and the right proof is given.
基金Supported by the Natural Scientific Research Foundation of Yunnan Province(2000A0001-1M)the Scientific Foundations of Education Commisison of Yunnan Province(9911126)
文摘In this paper, an error is firstly pointed out in the proof of the main theorems (Theorem 4 and Theorem 6) in [1]. Then the error is corrected and the right proof is given.