论文标题
四个分数的线路中的线
Lines in quasi-metric spaces with four points
论文作者
论文摘要
欧几里得平面中的一组非共线点定义了至少n个不同的线。 2008年,陈和奇瓦塔尔(Chen andChvátal)猜想,在公制空间中,相同的结果是正确的,以实现线路的适当定义。最近,该猜想是在准中空间的背景下研究的。在这项工作中,我们证明在四个点A,B,C和D上有一个准中空间,其中间是B = {(c,a,b),(a,b,c),(a,b,c),(d,b,a),(b,a,d)}。然后,这个空间只有三行,没有四个分。此外,我们表明,在四个点上的任何准中空间与该属性的关系是同构的。由于B不是公式,因此我们得到Chen和Chvátal的猜想对于在四个点上的任何度量空间有效。
A set of n non-collinear points in the Euclidean plane defines at least n different lines. Chen and Chvátal in 2008 conjectured that the same results is true in metric spaces for an adequate definition of line. More recently, this conjecture was studied in the context of quasi-metric spaces. In this work we prove that there is a quasi-metric space on four points a, b, c and d whose betweenness is B={(c,a,b),(a,b,c),(d,b,a),(b,a,d)}. Then, this space has only three lines none of which has four points. Moreover, we show that the betweenness of any quasi-metric space on four points with this property is isomorphic to B. Since B is not metric, we get that Chen and Chvátal's conjecture is valid for any metric space on four points.