9. The computer system of claim 8 wherein: the parse tree nodes include a root node, one or more interior nodes, and a plurality of terminal nodes representing linguistic elements of the natural language sentence, the particular node corresponding to the element of interest being one of the terminal nodes; each of the parse tree nodes has an associated linguistic identifier; the extracting includes traversing the parse tree along a traversal path starting at the particular terminal node corresponding to the element of interest and ending at the root node; and the syntactic information includes a sequence of linguistic identifiers associated with respective nodes of the traversal path in order of traversal.
9. The computer system of claim 8 wherein: the parse tree nodes include a root node, one or more interior nodes, and a plurality of terminal nodes representing linguistic elements of the natural language sentence, the particular node corresponding to the element of interest being one of the terminal nodes; each of the parse tree nodes has an associated linguistic identifier; the extracting includes traversing the parse tree along a traversal path starting at the particular terminal node corresponding to the element of interest and ending at the root node; and the syntactic information includes a sequence of linguistic identifiers associated with respective nodes of the traversal path in order of traversal. 11. The computer system of claim 9 wherein: the parse tree includes a first node corresponding to a linguistic element of the natural language sentence which is a form of the verb “to be” and has a semantic role, and includes a second node associated with a linguistic element of the natural language sentence having a semantic argument index corresponding to the semantic role; and the traversal path includes a discontinuous jump of the parse tree from the first node directly to the second node.