Abstract: A system for analyzing similarities between a first and second corpus or between a set of concepts and a corpus uses natural language processing and machine intelligence methods to replace terms or phrases in the corpus with concepts, determine the frequency of each concept in the corpus, and convert the corpus into a concept frequency file to enable easy comparison of the two corpuses or easy retrieval of items from the corpus that contain concept. Difference analysis and a combination of content and spectral analysis may be employed.

Abstract: This invention comprises a series of steps which transforms one or more natural language expressions into a single, well-formed formal language representation. Each natural language expression is partially parsed into simple fragments, each of which is then associated with one or more short formal expressions. Each formal expression is constructed in such a way as to contain one or more placeholder variables, each of which is associated with one or more attributes to constrain the types of entities that each variable can potentially represent. The resulting plurality of formal expressions is then filtered for relevance within a given context, and the surviving expressions manipulated based upon a plurality of rules, which are cognizant of the attributes associated with each variable contained therein. A user is then presented with the resulting plurality of formal expressions, whereupon the user optionally selects, rejects, adds to, logically connects and otherwise manipulates each member of said plurality.