orms of Grammars, Finite Automata, Abstract Families, and Closure Properties of Multiset Languages . . . . 135 Manfred Kudlek, Victor Mitrana On Multisets in Database Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Gianfranco Lamperti, Michele Melchiori, Marina Zanella Tolerance Multisets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 Solomon Marcus Fuzzy Multisets and Their Generalizations . . . . . . . . . . . . . . . . . . . 225 Sadaaki Miyamoto