A semigroup-theoretical view of direct-sum decompositions and associated combinatorial problems

Nicholas R. Baeth, Alfred Geroldinger, David J. Grynkiewicz +1

Let $R$ be a ring and let $\mathcal{C}$ be a small class of right $R$-modules which is closed under finite direct sums, direct summands, and isomorphisms. Let $\mathcal V (\mathcal…