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Problems related to a de Bruijn - Erdős theorem

Xiaomin Chen·Vašek Chvátal
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Abstract

De Bruijn and Erdős proved that every noncollinear set of n points in the plane determines at least n distinct lines. We suggest a possible generalization of this theorem in the framework of metric spaces and provide partial results on related extremal combinatorial problems.

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Xiaomin Chen, Vašek Chvátal. 2006-10-01. Problems related to a de Bruijn - Erdős theorem. https://arxiv.org/abs/math/0610036

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