On the mention level, we considered the head word (HD) of the mention, and following the edges in the dependency tree, we considered the left-most and right-most children of the head word (HDLMC and HDRMC), the left and right siblings of the head word (HDLS and HDRS), as well as the governor 1 of the head word (HDGOV).
the features marked with a dagger † originate from the Soon et al.