International Journal of Mathematics and Mathematical Sciences
Volume 2007 (2007), Article ID 10836, 5 pages
doi:10.1155/2007/10836

A Note on -Cofinitely Supplemented Modules

Yongduo Wang and Qing Sun

Department of Applied Mathematics, Lanzhou University of Technology, Lanzhou 730050, China

Abstract

Let R be a ring and M a right R-module. In this note, we show that a quotient of an -cofinitely supplemented module is not in general -cofinitely supplemented and prove that if a module M is an -cofinitely supplemented multiplication module with Rad(M)M, then M can be written as an irredundant sum of local direct summand of M. An extension of the result of Calisici and Pancar [1], here it is shown that an arbitrary module is cofinitely semiperfect if and only if it is an (amply) cofinitely supplemented by supplements which have projective covers.