Apart from its application to machine translation, the encoder-decoder or sequence-to-sequence (seq2seq) paradigm has been successfully applied to monolingual text-to-text tasks including simplification <cite>(Nisioi et al., 2017)</cite> , paraphrasing (Mallinson et al., 2017) , style transfer (Jhamtani et al., 2017) , sarcasm interpretation (Peled and Reichart, 2017) , automated lyric annotation (Sterckx et al., 2017) and dialogue systems (Serban et al., 2016) .