Can subsums and subtensors be defined as diagrams? Tensors not needing to be subtensors sounds to me like subsums/​subtensors should be fronter-row citizens than sums/​tensors.
Can subsums and subtensors be defined as diagrams? Tensors not needing to be subtensors sounds to me like subsums/​subtensors should be fronter-row citizens than sums/​tensors.