This dependency relationship offers a very condensed representation of the information needed to assess the relationship in the forms of the dependency tree (Culotta and Sorensen, 2004) or the shortest dependency path (Bunescu and Mooney, 2005) that includes both entities.
when the parse tree corresponding to the sentence is derived using derivation rules from the bottom to the top, the wordword dependencies extend upward, making a unique head child containing the head word for every non-terminal constituent.