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arXiv cs/9801101cs.AI
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知识的增量编译

Incremental Recompilation of Knowledge

G. Gogic, C. H. Papadimitriou, M. Sideri

摘要:

用Horn公式自上而下逼近一般公式(分别是它的霍恩包络和霍恩核心)由塞尔曼和考茨提出,(1991,1996)作为一种“知识汇编”的形式,支持快速近似推理;在负面方面,该方案是静态的,因为它不支持更新,并且具有Kavvadias指出的某些复杂性缺点,Papadimitriou和Sideri(1993年)。另一方面,在文献中提出的许多理论更新和修订的框架和方案受到严重的复杂性理论障碍的困扰,即使在霍恩的情况下,如Eiter和Gottlob(1992)所指出的,并在本文中进一步证明。更基本的是,这些方案不是归纳的,因为它们可能在一次更新中丢失所表示的公式集的任何积极性质(小尺寸,Horn结构等)。在本文中,我们提出了一个新的计划,增量重新编译,它结合了霍恩近似和基于模型的更新,该计划是归纳和非常有效的,自由的问题,其成分。一组公式由上下Horn近似表示。为了更新,我们用其最小变化更新的Horn包络替换上Horn公式,同样地,用其更新的Horn核心替换下Horn公式;使该方案成为可能的关键事实是,当底层公式是由子句对Horn公式进行最小变化更新的结果时,Horn包络和核心很容易计算。我们推测,有效的算法是可能的更复杂的更新。

英文摘要:

Approximating a general formula from above and below by Horn formulas (its Horn envelope and Horn core, respectively) was proposed by Selman and Kautz (1991, 1996) as a form of ``knowledge compilation,'' supporting rapid approximate reasoning; on the negative side, this scheme is static in that it supports no updates, and has certain complexity drawbacks pointed out by Kavvadias, Papadimitriou and Sideri (1993). On the other hand, the many frameworks and schemes proposed in the literature for theory update and revision are plagued by serious complexity-theoretic impediments, even in the Horn case, as was pointed out by Eiter and Gottlob (1992), and is further demonstrated in the present paper. More fundamentally, these schemes are not inductive, in that they may lose in a single update any positive properties of the represented sets of formulas (small size, Horn structure, etc.). In this paper we propose a new scheme, incremental recompilation, which combines Horn approximation and model-based updates; this scheme is inductive and very efficient, free of the problems facing its constituents. A set of formulas is represented by an upper and lower Horn approximation. To update, we replace the upper Horn formula by the Horn envelope of its minimum-change update, and similarly the lower one by the Horn core of its update; the key fact which enables this scheme is that Horn envelopes and cores are easy to compute when the underlying formula is the result of a minimum-change update of a Horn formula by a clause. We conjecture that efficient algorithms are possible for more complex updates.

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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