Inclusion measures in intuitionistic fuzzy set theory

Twenty years after their inception, intuitionistic fuzzy sets are on the rise towards making their "claim to fame". Competing alongside various other, often closely related, formalisms, they are catering to the needs of a more demanding and rapidly expanding knowledge-based systems industry. In this paper, we develop the notion of a graded inclusion indicator within this setting, drawing inspiration from related concepts in fuzzy set theory, yet keeping a keen eye on those particular challenges raised specifically by intuitionistic fuzzy set theory. The use of our work is demonstrated by its applications in approximate reasoning and non-probabilistic entropy calculation.