At the sentence level, Long-Short Term Memory Networks (LSTMs; Hochreiter and Schmidhuber 1997) learn representations for EDUs and larger constituents, whereas at the document level, LSTMs learn representations for entire sentences.
given a constituent sequence C, the probability of forming the structure sequence Y str is written as: where the u str t represents the unary potential score of structure node l t = y t , depending on constituents c t and c t+1 .