For each pair (Qi, Qj) of reference points and each real number r there is a unique hyperplane h QiQj such that d(P, Qi)2 - d(P, Qj)2 = r for points P in h. Take n reference point...
The volume of the n-dimensional polytope nx := fy 2 Rn : yi 0 and y1 + + yi x1 + + xi for all 1 i ng for arbitrary x := x1; : : : ; xn with xi 0 for all i de nes a polyn...
We discuss methods for the generation of oriented matroids and of isomorphism classes of oriented matroids. Our methods are based on single element extensions and graph theoretica...
We study the map which sends vectors of polynomials into their Wronski determinants. This defines a projection map of a Grassmann variety which we call a Wronski map. Our main res...
Let V be a vector space of dimension d over a field K and let A be a central arrangement of hyperplanes in V. To answer a question posed by K. Aomoto, P. Orlik and H. Terao constru...