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Soft set theory. (English) Zbl 1032.03525
Summary: The authors study the theory of soft sets initiated by Molodtsov. The authors define equality of two soft sets, subsets and supersets of a soft set, the complement of a soft set, the null soft set, and the absolute soft set, along with some examples. Soft binary operations like AND, OR and also the operations of union and intersection are defined. De Morgan’s laws and a number of results are verified in soft set theory.

MSC:
03E72Fuzzy set theory
68T37Reasoning under uncertainty