We establish a discrete multivariate mean value theorem for the class of positive maximum component sign preserving functions. A constructive and combinatorial proof is given based upon a simplicial algorithm and vector labeling. Moreover, we apply this theorem to a discrete nonlinear...

This discussion paper resulted in a publication in 'Discrete Optimization', 2007, 4, 315-321.<P> In this paper an algorithm is proposed to find an integral solution of (nonlinear) complementarity problems. The algorithm starts with a nonnegative integral point and generates a unique sequence of...</p>

This discussion paper resulted in a publication in the 'SIAM Journal on Optimization', 2006, 16, 854-870. <P> It is well known that an upper semi-continuous compact- and convex-valued mapping fi from a nonempty compact and convex set X to the Euclidean space of which X is a subset has at least one...</p>

This discussion paper led to a publication in <A href="http://www.sciencedirect.com/science/article/pii/S0377221711004498">'European Journal of Operational Research'</A>, 214(3), 493-500.<P>We study the existence problem of a zero point of a function defined on a finite set of elements of the integer lattice of the n-dimensional Euclidean space. It is assumed that the set is...</p></a>

<I>Abstract</I><p> See document.<p>

Tucker's well-known combinatorial lemma states that for any given symmetric triangulation of the n-dimensional unit cube and for any integer labeling that assigns to each vertex of the triangulation a label from the set {1,2,...n,-1,-2,....-n} with the property that antipodal vertices on the...

In a standard general equilibrium model it is assumed that there are no price restictions and that prices adjust infinitely fast to their equilibrium values. In this paper the set of admissible prices is allowed to be an arbitrary convex set. For such an arbitrary set it cannot be guaranteed...

We study an economy where a collection of indivisible goods are sold to a set of buyers who want to buy at most one good. We characterize the set of Walrasian equilibrium price vectors in such an economy using sets of overdemanded and underdemanded goods. Further, we give characterizations for...

This paper analyzes the problem of selling a number of indivisible items to a set of unit-demand bidders. An ascending auction mechanism called the Excess Demand Ascending Auction (EDAA) is defined. The main results demonstrate that EDAA terminates in a finite number of iterations and that the...

In this paper we present two general results on the existence of a discrete zero point of a function from the <I>n</I>-dimensional integer lattice Z<SUP><I>n</SUP></I> to the <I>n</I>-dimensional Euclidean space R<SUP><I>n</SUP></I>. Under two different boundary conditions, we give a constructive proof using a combinatorial argument based on a...</i></sup></i></i></sup></i>