1. An index generator for generation of an index for information retrieval for a corpus, comprising: an inflectional analyzer for receiving a corpus as an input, the inflectional analyzer producing a lemmatized corpus having an identified base form and associated inflection for each word of the corpus; a disambiguator for receiving the lemmatized corpus as an input, the disambiguator applying syntactic knowledge to disambiguate identified multiple inflected base forms in the lemmatized corpus representing the same word in the original corpus to produce a disambiguated corpus; a derivational generator for receiving the disambiguated corpus as an input and produce an expanded corpus including all possible derivations for each word in the disambiguated corpus; and a transformational analyzer for receiving the expanded corpus as an input and applying a grammar and a metagrammar to the expanded corpus to conflate term variants in the expanded corpus, the transformational analyzer producing an index to the corpus, the index having a minimum number of variants.