arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1503.08792cs.LOcs.DMmath.COmath.LO
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用计数逻辑标识的图

Graphs Identified by Logics with Counting

Sandra Kiefer, Pascal Schweitzer, Erkal Selman

摘要:

我们对图进行分类,更一般地说,对由C2标识的有限关系结构进行分类,即具有计数的双变量一阶逻辑。使用这种分类,我们表明,它可以决定在几乎线性的时间是否一个结构被确定为C2。我们的分类意味着,对于这个逻辑识别的每个图,它的所有顶点颜色版本也被识别。对于有限关系结构,也有类似的说法。我们提供了解决线性时间有限结构反演问题的构造。这个问题以前已被证明是多项式时间可解的马丁奥托。对于图,我们得出结论,每个C2-等价类包含一个图,其轨道正是其顶点集的C2-划分的类,并有一个单一的自同构证明这一事实。对于一般k,我们表明,这种说法是不正确的,通过提供的例子,图的大小线性k确定的C3,但其轨道分区是严格精细比CK-分区。我们还提供了确定的图形,顶点颜色的版本,不确定的CK。

英文摘要:

We classify graphs and, more generally, finite relational structures that are identified by C2, that is, two-variable first-order logic with counting. Using this classification, we show that it can be decided in almost linear time whether a structure is identified by C2. Our classification implies that for every graph identified by this logic, all vertex-colored versions of it are also identified. A similar statement is true for finite relational structures. We provide constructions that solve the inversion problem for finite structures in linear time. This problem has previously been shown to be polynomial time solvable by Martin Otto. For graphs, we conclude that every C2-equivalence class contains a graph whose orbits are exactly the classes of the C2-partition of its vertex set and which has a single automorphism witnessing this fact. For general k, we show that such statements are not true by providing examples of graphs of size linear in k which are identified by C3 but for which the orbit partition is strictly finer than the Ck-partition. We also provide identified graphs which have vertex-colored versions that are not identified by Ck.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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