arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.04454cs.LO
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强等价逻辑程序的句法研究

A Syntactic Approach to Studying Strongly Equivalent Logic Programs

Zhizheng Zhang, Shutao Zhang, Yanghe Feng, Bin Wang

摘要:

在应答集程序设计领域中,如果两个逻辑程序在任意扩展下通常等价,则它们是强等价的。这一性质为研究逻辑程序的许多方面提供了理论基础,如程序简化和转换等。因此,ASP及其扩展(如LPMLN)的强等价性得到了广泛的研究。本文提出了一种研究逻辑程序强等价性的句法方法,它提供了一些有趣的结果,有助于我们从一个新的角度理解强等价性。首先,我们提出了独立集的概念和逻辑程序的五种句法变换(S-* 变换)。在ASP和LPMLN的背景下,我们研究了S-* 变换的强等价(SE)和非强等价(NSE)保持性质。其次,基于S-* 变换的性质,我们提出了一个全自动的算法来发现ASP和LPMLN程序保持强等价的语法条件(SE条件)。为了有效地发现SE-条件,我们提出了四种方法来改进算法。第三,我们提出了一个初步的方法来简化已发现的SE-条件,并报告了几种LPMLN程序的简化SE-条件。在此基础上,我们对所发现的SE-条件和存在的问题进行了讨论。最后,我们提出了一个比较SE条件发现方法在本文和相关的工作。

英文摘要:

In the field of Answer Set Programming (ASP), two logic programs are strongly equivalent if they are ordinarily equivalent under any extensions. This property provides a theoretical foundation for studying many aspects of logic programs such as program simplification and transformation etc. Therefore, strong equivalence has been investigated extensively for ASP and its extensions such as LPMLN. In this paper, we present a syntactic approach to studying the strong equivalence of logic programs, which provides several interesting results and would help us understand the strong equivalence from a new perspective. Firstly, we present the notions of independent sets and five kinds of syntactic transformations (S-* transformations) for logic programs. And we investigate the strong equivalence (SE) and non-strong equivalence (NSE) preserving properties of the S-* transformations in the contexts of ASP and LPMLN. Secondly, based on the properties of the S-* transformations, we present a fully automatic algorithm to discover syntactic conditions that preserve strong equivalences (SE-conditions) of ASP and LPMLN programs. To discover the SE-conditions efficiently, we present four kinds of approaches to improve the algorithm. Thirdly, we present a preliminary method to simplify the discovered SE-conditions and report the simplified SE-conditions of several kinds of LPMLN programs. After that, we present a discussion on the discovered SE-conditions and some existing problems. Finally, we present a comparison between SE-conditions discovering approaches in this paper and in the related work.

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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