Type-2 fuzzy sets and their application in decision-making summary. General concepts

An overview of the basic concepts and algebraic operations related to type-2 fuzzy sets and type-2 fuzzy relations is given. In particular, interval fuzzy type-2 set are considered, among which interval trapezoidal and triangular fuzzy type-2 sets are most common. Standard arithmetic operations with interval fuzzy type-2 set are presented. In addition, several scales of linguistic variables are discussed.