Relatively Lifting Modules.

We consider a generalization of lifting modules relative to a class $\mathcal{A}$ of modules and a proper class 피 of short exact sequences of modules. These modules will be called 피-$\mathcal{A}$-lifting. We establish characterizations of modules with the property that every direct sum of copies of them is 피-$\mathcal{A}$-lifting. [ABSTRACT FROM AUTHOR]