It is well known that an upper semi-continuous compact- and convex-valued mapping ö from a nonempty compact and convex set X to the Euclidean space of which X is a subset has at least one stationary point, being a point in X at which the image ö (x)has a nonempty intersection with the normal...

AMS classifications: 47H10; 54H25; 55M20; 90C26; 90C33; 91B50;

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 f§1;§2; ¢ ¢ ¢ ;§ng with the property that antipodal vertices on the...

The well known Sperner lemma states that in a simplicial subdivision of a simplex with a properly labeled boundary there is a completely labeled simplex. We present two combinatorial theorems on polytopes which generalize Sperner's lemma.Using balanced simplices, a generalized concept of...

In this paper we study the existence problem of a zero point of a function defined on a finite set of elements of the integer lattice Zn of the n-dimensional Euclidean space IRn. It is assumed that the set is integrally convex, which implies that the convex hull of the set can be subdivided in...

AMS classifications: 54H25, 65K10, 49J53, 68W25

AMS classifications: 90C33, 90C26, 91B50.

AMS subject classifications: 90B18, 91A12, 91A43.