Document Type : Research Articles


1 Department of Mathematics, University of Mazandaran, Babolsar, Iran

2 Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaaran



Let R be a ring and M a right R-module. We call M, a \delta(M)-coretractable module if for every proper submodule N of M containing \delta(M), there is a nonzero homomorphism from M=N to M. We investigate some conditions which under two concepts \delta(M)-coretractable and coretractable coincide. For a ring R, we prove that R is right Kasch if and only if R_R is