As they do, we have used the Penn treebank (Marcus et al., 1994) for our experiments, employing the syntactic annotations that it provides for evaluation purposes only.
we have used WSJ10, composed of 6842 sentences, which is the subset of the Wall Street Journal section of the Penn Treebank, containing only those sentences of 10 words or less after removing punctuation and null elements, such as $, ", etc.