A document processing apparatus uses a synonym dictionary to substitute words and phtrases in a document by other synonymous words and phrases. At this juncture, the frequency of use of the words in a document is counted, and the words which have more frequency of use are made the objects of the substitution....http://www.google.de/patents/US5742834?utm_source=gb-gplus-sharePatent US5742834 - Document processing apparatus using a synonym dictionary
