A General Computational Treatment of Comparatives for Natural Language Question Answering

We discuss the techniques we have developed and implemented for the cross-categorial treatment of comparatives in TELl, a natural language questionanswering system that's transportable among both application domains and types of backend retrieval systems. For purposes of illustration, we shall consider the example sentences "List the cars at least 20 inches more than twice as long as the Century is wide" and "Have any US companies made at least 3 more large cars than Buick?" Issues to be considered include comparative inflections, left recursion and other forms of nesting, extraposition of comparative complements, ellipsis, the wh element "how', and the translation of normalized parse trees into logical form.