Double Fuzzy $\delta$-Continuous Functions in Double Fuzzy Topological Spaces

In this paper, we introduce $(\mathfrak{r}, \mathfrak{s})$-$\delta$-fuzzy closed sets in double fuzzy topological spaces and investigate some of their properties. Moreover, we introduce the concept of double fuzzy $\delta$-continuous functions. Several interesting properties and characterizations are introduced and discussed. Furthermore, the relationships among the new concepts are introduced and established with some interesting counterexamples.