Abstract
The notion of interval valued intuitionistic fuzzy sets was introduced by Atanassov and Gargov as a generalization of the notion of intuitionistic fuzzy sets and interval valued fuzzy sets. In this paper, we initiate a study on interval valued intuitionistic fuzzy sets in -semihypergroups. We introduce the notions of interval valued intuitionistic fuzzy left (right, two sided) -hyperideal, interval valued intuitionistic fuzzy bi--hyperideal and interval valued intuitionistic fuzzy (1,2) -hyperideal in a -semihypergroup and some properties of them are obtained. We use the interval valued intuitionistic fuzzy left, right, two-sided and bi--hyperideals to characterize some classes of -semihypergroups. We also introduce the notion of an interval valued intuitionistic fuzzy (resp. )-hypersystem of a -semihypergroup and some properties of them are investigated.