13. The method of claim 12 wherein hierarchical head nodes are created for one or more of the constituent nodes of the parsed natural language sentence or phrase based upon the head analysis.
12. The method of claim 10 and further comprising the step of: performing a head analysis of the parsed natural language sentence or phrase; and creating the unordered hierarchical dependency structure based upon a semantic relation between constituents of the parsed natural language sentence or phrase derived using the head analysis.