create for themselves and hopefully to extend, mechanics. The book under review not only falls to nurture invention in mechanics but it makes it difficult to comprehend why such work is necessary at all.

Fuzziness is discussed in the context of multivalued lo&, and a corresponding view of fuzzy sets is given. Fuzzy random variables are introduced as random variables whose values are not real but fuzzy numbers, and subsequently redefined as a particular kind of fuzzy set. Expectations of fuzzy random variables, characteristic f~cti~ of fuzzy events, probabilities connected to fuzzy random variables, and conditional expectations and probabilities relating to fuzzy random variabIes are defined as images of the fuzzy set representing the fuzzy random variable under appropriate mappings. Several theorems, some of which relate to independent fuzzy random variables, are proved.

No abstract

Fuzzy sets theory may be used to solve multiple-attribute decision problems under uncertainty.

Robust control systems may successfully be designed by ~'=-optimization, in particular, by reformulating the design problem as a mixed sensitivity problem.Key Words--~=-optimal control; robust control.Abstract--The paper presents a tutorial exposition of ~=-optimal regulation theory, emphasizing the relevance of the mixed sensitivity problem for robust control system design.