A directed set can be used to establish contexts for linguistic concepts: for example, to aid in answering a question, to refine a query, or even to determine what questions can be answered given certain knowledge. A directed set includes a plurality of elements and chains relating the concepts. One...http://www.google.de/patents/US7152031?utm_source=gb-gplus-sharePatent US7152031 - Construction, manipulation, and comparison of a multi-dimensional semantic space
