Before revision:  Projection of the decoder states onto such interpretable embedding space shows that Seq2Seq training to predict sequences using gradient-descent back propagation effectively performs dimension reduction consisting of only a small percentage of dimensions of the network's hidden units.
After revision:  Projection of the decoder states of RNN Seq2Seq training to predict sequences using gradient-descent back propagation effectively performs dimension reduction consisting of only a small percentage of dimensions of the network's hidden units.