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arXiv 2109.02065math.RAcs.CC
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G-不变项的局部-整体性质

The local-global property for G-invariant terms

Alexandr Kazda, Michael Kompatscher

摘要:

对于某些Maltsev条件$Σ$,检查有限代数$\mathbf A$是否在有界大小的子集上局部满足$Σ$就足够了,以便决定$\mathbf A$是否满足$Σ$(全局)。这种局部-全局性质是决定Maltsev条件的易处理性结果的主要已知来源。本文研究了$G$ -项存在的局部-整体性质,即$n$ -元项在按照置换群$G \leq$ Sym($n$)置换其变量时不变.我们的结果特别意味着,所有的循环回路条件(在Bodirsky,Starke和Vucaj的意义下)具有局部-全局性质(因此可以在多项式时间内决定),而对称项的arity $n>2$没有它。

英文摘要:

For some Maltsev conditions $Σ$ it is enough to check if a finite algebra $\mathbf A$ satisfies $Σ$ locally on subsets of bounded size, in order to decide, whether $\mathbf A$ satisfies $Σ$ (globally). This local-global property is the main known source of tractability results for deciding Maltsev conditions. In this paper we investigate the local-global property for the existence of a $G$-term, i.e. an $n$-ary term that is invariant under permuting its variables according to a permutation group $G \leq$ Sym($n$). Our results imply in particular that all cyclic loop conditions (in the sense of Bodirsky, Starke, and Vucaj) have the local-global property (and thus can be decided in polynomial time), while symmetric terms of arity $n>2$ fail to have it.

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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