Problem: Given a finite free resolution C of $\mathbb{Z}$ over $\mathbb{Z}G$ I would like to consider the free resolution $C \otimes C$. Then of course in this new resolution I'm going to have direct sums of tensor products. In sage I'm working with CombinatorialFreeModule, there is a way to defining a direct sum over CombinatorialFreeModule_Tensor?
Thanks in advance.
