Fuzzy Set Theory and Information Retrieval Systems.

Motivation for and basis of the Fuzzy set theory are explained. The operations with and the relations between these sets are shown. The problems, which are connected to the application of the Fuzzy set theory to models in information science (specially in information retrieval systems), are discussed in detail. Furthermore the author lists some retrieval strategies, which are declared to be fuzzy-theoretic. The author finishes with consideration of the appropriate applicability of Fuzzy set theory in different areas. (Edited author abstracft)