US Patent 7149748 Expanded inverted index

Indexing documents is accomplished by generating an inverted index for a collection of one or more documents. The inverted index includes an inverted list for an index term appearing in one or more of the documents in the collection, and one or more postings. A posting includes a document identifier identifying a document in the collection of documents, a position identifier identifying a position of the index term in the document; and proximity information specifying whether the index term is positioned in a predefined proximal relationship between the index term and another a second index term in the document.