Renaming a set of non-Horn clauses
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Several extensions of the logic programming language Prolog to non-Horn clauses use case anlaysis to handle non-Horn clauses. In this paper, analytical and empirical evidences are presented to show that, by making a set of clauses less “non-Horn” using predicate renaming, the performance- of these case-analysis based procedures can be improved significantly. In addition, the paper also investigated the problem of efficiently constructing a predicate renaming that reduces the degree of “non-Hornness” of a clause set maximally. It is shown that this problem of finding a predicate renaming to achieve minimal “non-Hornness” is NP-complete.
Keywordslogic for artificial intelligence (AI) automated theorem proving logic programming Horn and non-Horn sets predicate renaming NP-completeness
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- Clocksin W F, Mellish C S. Programming in Prolog. Springer-Verlag, 1981.Google Scholar
- Lloyd J W. Foundations of Logic Programming. Springer-Verlag, 1987.Google Scholar
- Kowalski R A. Predicate logic as a programming language. InInformation Processing 74, Jack Rosenfeld (ed.), North-Holland, 1974, pp.569–574.Google Scholar
- Reed D W, Loveland D W. Near-Horn Prolog and the ancestry family of procedures.Annals of Mathematics and Artificial Intelligence, 1995, 14.Google Scholar
- Nie X. Complexities of non-Horn clause logic programming. InMethodologies for Intelligent Systems 5, Ras Z, Zemankova M, Emrich M (eds.), 1990, p.539–544.Google Scholar
- Nie X. How well are non-Horn clauses handled. InLecture Notes in Computer Science 542, Ras Z, Zemankova M (eds.), Springer-Verlag, 1991, pp.580–588.Google Scholar
- Mitchell D, Selman B, Levesque H. Hard and easy distributions of SAT problems. InProceeding of AAAI-92, San Jose, CA, July 12–16, 1992, pp.459–465.Google Scholar
- Garey M R, Johnson D S. Computers and Intractability: A Guide to the Theory of NP-Completeness. W.H. Freeman Company, 1979.Google Scholar