include parenthesized expressions that are marked as noun-phrases, such as (See related story: "Fed Ready to Inject Big Funds": WSJ Oct. 16, 1989); false negatives can be headlines having a main verb, e.g., Population Drain Ends For Midwestern States.
nevertheless, many popular grammars for unsupervised parsing behave as if a word had to generate all of its children (to one side) -or at least their count -before allowing any of these children themselves to recurse.