I'm trying to read this paper describing Google's LSTM architecture for machine translation. It features this diagram on page 4:
I'm interested in the encoder block, on the left. Apparently, the pink and green cells are LSTMs. However, I can't tell if the x-axis is space or time. That is, are the LSTM cells on a given row all the same cell, with time flowing forward from left to right? The diagram on the next page in the paper seems to suggest that.