论文标题
纠缠
Entanglements
论文作者
论文摘要
罗伯逊(Robertson)和西摩(Seymour)为每棵树的分类$ g $构建,可有效区分$ g $的所有缠结。尽管这些分解的所有先前结构本质上都是迭代的,还是不是规范性的,但我们提供了一个明确的一步结构,该结构是规范的。关键成分是缠结的“局部特性”的公理化。还讨论了对本地有限图和矩形的概括。
Robertson and Seymour constructed for every graph $G$ a tree-decomposition that efficiently distinguishes all the tangles in $G$. While all previous constructions of these decompositions are either iterative in nature or not canonical, we give an explicit one-step construction that is canonical. The key ingredient is an axiomatisation of 'local properties' of tangles. Generalisations to locally finite graphs and matroids are also discussed.