R-intersections and R-unions of neutrosophic cubic sets
R-unions and R-intersections of T-external (Iexternal, F-external) neutrosophic cubic sets are considered. Examples to show that the R-intersection and R-union of Texternal (I-external, F-external) neutrosophic cubic sets may not be a T-external (I-external, F-external) neutrosophic cubic set are provided. Conditions for the R-union and R-intersection of T-external (I-external, F-external) neutrosophic cubic sets to be a T-external (I-external, F-external) neutrosophic cubic set are discussed.