Under the assumption that constituents generally move as a whole, we predict the probability of each given ordering of modifiers independently.
we make the following simplifying assumption (where c is a function returning the set of nodes modifying t): Furthermore, we assume that the position of each child can be modeled independently in terms of a head-relative position: Figure 3a demonstrates an aligned dependency tree pair annotated with head-relative positions; Figure 3b presents the same information in an alternate tree-like representation.