Graph Minors .XII. Distance on a Surface
Graph Minors .XII. Distance on a Surface
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图未成年人.XII。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
P. Seymour
中科院分区：
文献类型：
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作者：
N. Robertson;P. Seymour
设Γ是画在非球面连通曲面上的图。如果每一条非零同伦闭曲线至少满足Γ θ次，则称之为“θ -代表”曲线。另外，Γ定义了一个关于π的度量，在前面的论文中讨论过。我们的目标是研究在绘图或曲面中进行局部更改对度量和“代表性”的影响。我们还重新制定更compcompersible的主要定理的早期文件在此度量。这些是以后要用到的引理。
Abstract Let Γ a graph drawn on a connected surface Σ which is not a sphere. It is " θ -representative" if every non-null-homotopic closed curve meets Γ at least θ times. Also, Γ defines a metric on Σ , discussed in an earlier paper. Our objective here is to study the effect on the metric and on the "representativeness" of making local changes in the drawing or in the surface. We also reformulate more compactly the main theorem of an earlier paper in terms of this metric. These are lemmas to be used later.