A de Bruijn - Erdos theorem and metric spaces
Ehsan Chiniforooshan, Vašek Chvátal · Discrete Mathematics & Theoretical Computer Science · 2011
Combinatorics De Bruijn and Erdos proved that every noncollinear set of n points in the plane determines at least n distinct lines. Chen and Chvatal suggested a possible generalization of this theorem in the framework of metric spaces. We provide partial results in this direction.