论文标题
Digraphs II的末端：拓扑观点
Ends of digraphs II: the topological point of view
论文作者
论文摘要
在一系列三篇论文中，我们开发了一个用于Digraphs的最终空间理论。在第二篇论文中，我们介绍了由Digraph $ d $形成的拓扑空间$ | d | $以及其末端并限制边缘。然后，我们表征那些被此空间压缩的挖掘物。此外，我们表明，如果$ | d | $是紧凑的，那么它是$ d $的有限收缩未成年人的倒数限制。为了说明使用此信息的使用，我们扩展到空间$ | d | $ $两个关于没有逐字化的有限挖掘的说明，这些陈述是无限的挖掘。第一个陈述是每个顶点的内度等式等级的条件是有限欧拉的挖掘的表征。第二个陈述是通过封闭的汉密尔顿步道的存在来表征有限有限的挖掘。
In a series of three papers we develop an end space theory for digraphs. Here in the second paper we introduce the topological space $|D|$ formed by a digraph $D$ together with its ends and limit edges. We then characterise those digraphs that are compactified by this space. Furthermore, we show that if $|D|$ is compact, it is the inverse limit of finite contraction minors of $D$. To illustrate the use of this we extend to the space $|D|$ two statements about finite digraphs that do not generalise verbatim to infinite digraphs. The first statement is the characterisation of finite Eulerian digraphs by the condition that the in-degree of every vertex equals its out-degree. The second statement is the characterisation of strongly connected finite digraphs by the existence of a closed Hamilton walk.
