For example, such input can be the output of the co-attention layer in Section 3.
the operation of this layer is defined as at time step t, the controller generates an interface vector i t for read and write operations and an output vector o t based on the input vector d t and the external memory content from the previous time step, M t−1 ∈ R p×q , where p is the memory size and q is the vector dimension of each memory.