In this work we introduce the concept of Atanassov’s intuitionistic fuzzy index of a hypergroupoid based on the notion of intuitionistic fuzzy grade of a hypergroupoid. We calculate it for some particular hypergroups, making evident some of its special properties.

Vector sequences which are stationary with respect to polynomial hypergroups arise in various fields, such as stochastic processes and difference equations. In this paper, we discuss analytic properties of these sequences, namely the representation and complexification of the vector sequence.

This paper presents a series of important results from the theory n-hypergroups. Connections with binary relations and lattices are presented. Special attention is paid to fundamental relation commutative relation. In particular, join n-spaces analyzed.

In this paper it has been studied the sequence of membership functions and of join spaces (see [7]), determined by a class of 1–hypergroups which are not complete (see [2]).

One studies the $HX$-hypergroups, corresponding to the Chinese hypergroups associated with the direct products of some ${bf Z}/n {bf Z},$ calculating their fuzzy grades.