In this note, we use Kunen’s notion of a signing to establish two theorems about the well-founded semantics of logic programs, in the case where we are interested in only (say) the positive literals of a predicate p that are consequences of the program. The first theorem identifies a class of programs for which the well-founded and Fitting semantics coincide for the positive part of p. The second theorem shows that if a program has a signing, then computing the positive part of p under the well-founded semantics requires the computation of only one part of each predicate. This theorem suggests an analysis for query answering under the well-founded semantics. In the process of proving these results, we use an alternative formulation of the well-founded semantics of logic programs, which might be of independent interest.

中文翻译：

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关于签名和有根据的语义

在这篇笔记中，我们使用 Kunen 的签名概念来建立关于逻辑程序的有根据的语义的两个定理，在这种情况下，我们只对（比如说）谓词的正字面量感兴趣p这是程序的后果。第一个定理确定了一类程序，其中有充分根据的语义和拟合语义对于p. 第二个定理表明，如果一个程序有一个签名，那么计算正数部分p在有根据的语义下，只需要计算每个谓词的一部分。该定理建议在有根据的语义下对查询回答进行分析。在证明这些结果的过程中，我们使用了逻辑程序的有根据的语义的替代表述，这可能具有独立的兴趣。