Consider the following sentence: This derivation expresses the following dependencies: We assume again that heads are generated before their modifiers or arguments, and that word-word dependencies are expressed by conditioning modifiers or arguments on heads.
the head words of arguments (such as Smith) are generated in the following manner: The head word of modifiers (such as yesterday) are generated differently: Like Collins (1999) and Charniak (2000), the SD model assumes that word-word dependencies can be defined at the maximal projection of a constituent.