Duality for a properly efficient solution of bilevel multiobjective fractional programming problems with extremal-value function

<p>In this paper, we establish some results regarding the optimality conditions and duality properties for properly efficient solutions of a constrained bilevel multiobjective fractional programming problem (P) with an extremal-value function. These results are obtained by applying a parametric approach to reduce the problem (P) to a parametric problem (P^&mu;) with &mu; &isin; R^p, and we obtain optimality conditions for properly efficient solutions for these problems. Furthermore, we define a dual problem of (P^&mu;) and we establish some results on duality.</p>