ALGEBRA & DISCRETE MATHEMATICS, cilt.19, sa.2, ss.283-294, 2015 (ESCI)
Let R be an arbitrary ring with identity and Al a right R-module with S = End(R)(M). In this paper, we study right R-modules 11 haying; the property for f, g is an element of End(R)(M) and for m is an element of M, the condition f gm = 0 implies gfm = 0. We prove that some results of symmetric rings can be extended to symmetric [nodules for this general setting.