## Intuitionistic fuzzy sets.(English)Zbl 0597.03033

Interval and fuzzy mathematics, Proc. Polish Symp., Poznań/Pol. 1983, 23-26 (1985).
[For the entire collection see Zbl 0587.00015.]
An intuitionistic fuzzy set A in the authors’ sense is characterized through a membership degree $$\mu_ A(x)$$ and a nonmembership degree $$\nu_ A(x)$$ in each point x of a universe of discourse, with $$0\leq \mu_ A(x)+\nu_ A(x)\leq 1$$ as a standard restriction. Some elementary set algebra for such intuitionistic fuzzy sets is sketched, and two operators – denoted $$\square$$ and $$\diamond$$ – are introduced making ordinary fuzzy sets out of intuitionistic ones and having essential properties of modal operators.
Reviewer: S. D. Latow

### MSC:

 03E72 Theory of fuzzy sets, etc. 03B45 Modal logic (including the logic of norms)

Zbl 0587.00015