计数无处稠密类
Counting on Nowhere Dense Classes
查看机构详情
- Humboldt-Universität zu Berlin(柏林洪堡大学)
机构由 AI 辅助整理,请以论文原文为准。
浏览论文内容
中文总结 AI 辅助
针对有效的无处稠密类,提出几乎线性时间预处理后常数时间计数查询和常数延迟枚举的算法,推广了现有关于一阶逻辑及带计数逻辑的结果。
中文摘要 AI 辅助
对于每个有效的无处稠密的关系结构类 $\mathcal{C}$,我们提出了一种算法,该算法在给定结构 $\mathcal{A} \in \mathcal{C}$ 和一阶公式 $\phi(x_1, \dots, x_k, y_1, \dots, y_\ell)$ 上运行一个几乎线性时间的预处理步骤。预处理之后,每当给定一个元组 $\bar{v} \in A^k$ 时,算法在常数时间内计算满足 $\mathcal{A} \models \phi(\bar{v}, \bar{w})$ 的元组 $\bar{w} \in A^\ell$ 的数量。在此基础上,我们提供了一种算法,用于在几乎线性时间预处理后,对最近引入的带计数的团守卫一阶逻辑(cgFOC)在有效的无处稠密类上进行常数时间查询回答和常数延迟枚举。这推广了在无处稠密类上关于一阶逻辑的测试和枚举结果 [Schweikardt, Segoufin, and Vigny, JACM 2022] 以及带计数的一阶逻辑 FOC1 的求值结果 [Grohe and Schweikardt, PODS 2018]。
英文摘要
For every effectively nowhere dense class $\mathcal{C}$ of relational structures, we present an algorithm that runs an almost-linear-time preprocessing step on a given structure $\mathcal{A} \in \mathcal{C}$ and a first-order formula $ϕ(x_1, \dots, x_k, y_1, \dots, y_\ell)$. After the preprocessing, whenever given a tuple $\bar{v} \in A^k$, the algorithm computes the number of tuples $\bar{w} \in A^\ell$ that satisfy $\mathcal{A} \models ϕ(\bar{v}, \bar{w})$ in constant time. Building on this, we provide an algorithm for constant-time query answering and constant-delay enumeration after almost-linear-time preprocessing for the recently introduced logic clique-guarded first-order logic with counting (cgFOC) on effectively nowhere dense classes. This generalises the testing and enumeration results for first-order logic [Schweikardt, Segoufin, and Vigny, JACM 2022] and the evaluation result for the first-order logic with counting FOC1 [Grohe and Schweikardt, PODS 2018] on nowhere dense classes.