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Reduction of cycle unification of type Cpg+r

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Abstract

In this paper a class of cycle unification problems called type Cpg+r is studied, and an intuitive representation method, calledthe position supergraph, is presented to analyze or reduce the cycle problem. A typical case of Cpg+r problems is considered and an algorithm is given, which transforms the original problem of Cpg+r that is of the exponential complexity into a new one that is of the linear complexity when using SLD resolution method. These results are of importance for practice and theory.

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References

  1. Bibel W, Holldobler S, Murtz J. Cycle unification. InProc. the Conference on Automated Deduction, Springer, Berlin, 1992, pp.94–108.

    Google Scholar 

  2. Bruning Stefan. Techniques for avoiding redundancy. InTheorem Proving Based on the Connection Method, Doctor’s Thesis D17, TH Darmstadt, 1994.

  3. Eder E. Properties of substitutions and unifications.Journal of Symbolic Computation, 1985, 1: 31–46.

    Article  MATH  MathSciNet  Google Scholar 

  4. Siekmann J H. Unification theory.Journal of Symbolic Computation, 1989, 7: 207–274.

    Article  MATH  MathSciNet  Google Scholar 

  5. Derienne P. Weighted graphs-tool for studying the halting problem and time complexity in term rewriting system and logic programming.Journal of Theoretical Computer Science, 1990, 75: 157–215.

    Article  Google Scholar 

  6. Schmidt-Schaub M. Implication of clauses is undecidable.Journal of Theoretical Computer Science, 1988, 59: 287–298.

    Article  Google Scholar 

  7. Wurtz Jorg. Unifying Cycle. Technical Report, DFKI, 1992.

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Authors and Affiliations

  1. Department of Computer Science, Fudan University, 200433, Shanghai, P.R. China

    Hu Yunfa

  2. Fachgebiet Intellektik, Technische Hochschule Darmstadt, Germany

    Wolfgang Bibel

Authors
  1. Hu Yunfa
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  2. Wolfgang Bibel
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Additional information

Partially supported by the DAAD of Germany, National Natural Science Foundation of China and National ‘863’ High-Tech Programme of China.

Hu Yunfa graduated from Department of Mathematics, Fudan University in 1964. He is now a Professor of Department of Computer Science, Fudan University and a member of Standing Committee of AI Institute of China. His research interests include logic programming, database and knowledge base, and AI.

Wolfgang Bibel is now a Professor of Fachgebiet Intellektik Technische Hochschule, Darmstadt, Germany and the inventor of the connection method in Logic.

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Hu, Y., Bibel, W. Reduction of cycle unification of type Cpg+r. J. of Comput. Sci. & Technol. 13, 18–24 (1998). https://doi.org/10.1007/BF02946610

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  • DOI: https://doi.org/10.1007/BF02946610

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