Similar to the work by Miwa and Bansal (2016), we concatenate the word representation together with the corresponding head word representation and dependency relation embedding as the input representation.
given a dependency edge (x h , x i , r) with x h as parent, x i as child and r as dependency relation, the representation at position i can be denoted as: where w i and w h are the word representations of the word x i and its parent x h , respectively.