The system is an improved version of attentionbased NMT system named RNNsearch (Bahdanau et al., 2015) where the decoder employs a conditional GRU layer with attention, consisting of two GRUs and an attention module for each step 5 .
equation (6) is replaced with the following two equations: Besides, for the calculation of relevance in equation (4), s j−1 is replaced withs j−1 .