On supplementation and generalized projective modules. (Q351627)

The authors introduce and study some concepts which generalize the notion of quasi-discrete module. For instance, a module \(M\) is called quasi-discrete if \(M=X\oplus Y\) for any submodules \(X\) and \(Y\) which are supplements of each other in \(M\). It is shown that generalized relative projectivity is an essential condition for direct sums of hollow modules to be quasi-discrete.