To integrate the syntactic information into sequential neural networks, we employ a syntactic encoder on top of the BiLSTM encoder.
given a syntactic dependency tree T , for each node n k in T , let C(k) denote the syntactic children set of n k , H(k) denote the syntactic head of n k , and L(k, •) be the dependency relation between node n k and those have a direct arc from or to n k .