We present the concepts of the limit superior and the limit inferior of a double sequence of fuzzy numbers and obtain several properties of these concepts. By using these concepts we also characterize the core of a double sequence of fuzzy numbers as a closed interval. Furthermore, we define Γ-convergence and the endograph metric convergence for a double sequence of fuzzy numbers, which are new types of convergence and investigate the relations between these types of convergence and the core of the sequence.

中文翻译：

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一串模糊数的核心

我们提出了模糊数双序列的上极限和下极限的概念，并获得了这些概念的几个性质。通过使用这些概念，我们还将模糊数的双序列的核心表征为闭区间。此外，我们定义了模糊数双序列的Γ-收敛和内图度量收敛，它们是新的收敛类型，并研究了这些类型的收敛与序列核心之间的关系。