If one hears the term thesaurus, one may think of two things: one is thesauri like Roget’s well-known thesaurus with words grouped and classified to help writers select the best word to convey a specific nuance of meaning; the other is thesauri as tools for indexers and searchers in information science with a listing of words and phrases authorized for use in an indexing system, together with relationships, variants and synonyms, and aids to navigation through the thesaurus (Craven, sec. 1). From this aspect a thesaurus is much more than just a dictionary with the definitions of terms, because it reveals different semantic relations as well. My work belongs to the second type; it is a so-called information retrieval thesaurus... (Introduction)