𝒢Θτi⋆τj-Fuzzy Closure Operator.

In this paper, a new class of fuzzy ideal sets, namely the r - (τ i , τ j) - θ -generalized fuzzy ideal closed sets, is introduced for fuzzy bitopological spaces in Šostak sense. This class falls strictly in between the class of r - (τ i , τ j) - θ -fuzzy ideal closed sets and the class of r - (τ i , τ j) -generalized fuzzy ideal closed sets. Furthermore, by using the class of r - (τ i , τ j) - θ -generalized fuzzy ideal closed sets we establish a new fuzzy closure operator which generates fuzzy bitopological spaces in Šostak sense. Finally, the (i , j) strongly- θ -fuzzy ideal continuous, (i , j) - θ -generalized fuzzy ideal continuous and (i , j) - θ -generalized fuzzy ideal irresolute mappings are introduced, and we show the (i , j) - θ -generalized fuzzy ideal continuous properly fuzzy ideal bitopological spaces in Šostak sense (for short, fibtss) in between (j , i) strongly- θ -fuzzy ideal continuous and (i , j) -generalized fuzzy continuous mappings. [ABSTRACT FROM AUTHOR]