The topological structure of the set of fuzzy numbers with the supremum metric. (English) Zbl 1522.54014
Summary: We study the family of all fuzzy sets of the \(n\)-dimensional Euclidean space, which are upper-semicontinuous, fuzzy convex and normal with compact supports contained in a non-degenerate convex subset Y, and prove that the following statements are equivalent: (i) The family of fuzzy sets with the topology induced by the supremum metric is homeomorphic to a non-separable Hilbert space whose weight is the cardinality of the set of all real numbers; (ii) the non-degenerate convex subset Y is topologically complete, or equivalently, it is a countable intersection of open sets in the n-dimensional Euclidean space.
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