Bilevel optimization problems with multivalued objective functions in both levels are first replaced by a problem with a parametric lower level using a convex combination of the lower level objectives. Thus a nonconvex multiobjective bilevel optimization problem arises which is then transformed into a parametric bilevel programming problem. The investigated problem has been considered in the paper \cite{FaAn10} using ideas from fuzzy optimization. It is one goal to correct some of the wrong ideas in the paper \cite{FaAn10}.
Citation
Working Paper Department of Mathematics and Computer Science, TU Bergakademie Freiberg, 2012