Sets, Fuzzy Sets, Multisets and Functions
John Lake · Journal of the London Mathematical Society · 1976
The concept of a set is familiar to most mathematicians and we refer the reader to [2] for details of the various axiomatizations of set theory. Fuzzy sets have been studied by Zadeh and others (see [4] and [9], for instance) and they attempt to model the notion of classes which do not have precisely defined criteria of membership. Multisets