Recently, sequence-to-sequence neural networks (Sutskever et al., 2014) have been applied to abstractive summarization (Nallapati et al., 2016; See et al., 2017; <cite>Paulus et al., 2017)</cite> following their success in both machine translation (Bahdanau et al., 2015; Luong et al., 2015b) , parsing (Luong et al., 2015a) and image captioning (Vinyals et al., 2015b) .