Skip to main content
SpringerLink
Log in

On parallel unification for Prolog

  • Regular Papers
  • Published:
New Generation Computing Aims and scope Submit manuscript

Abstract

Parallel unification algorithms are not nearly so numerous or well-developed as sequential ones. In order to estimate the improvement in efficiency which may be expected, we define and discuss an objective measure of the effect of parallelism on a sequential algorithm. This measure, known as thepotential parallel factor (PPF), is applied to parallel versions of the unification algorithms of Yasuura and Jaffar. The PPFs for these algorithms are measured on a variety of running Prolog programs to estimate what increase in speed may be expected in a Prolog environment from the use of parallelism. Other potential uses of parallelism may be evaluated by different applications of our general methods and techniques.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Chen, T. Y., Lassez, J. and Port, G. S., “Maximal Unifiable Subsets and Minimal Non-unifiable Subsets”,New Generation Computing, Vol. 4, pp. 133–152, 1986.

    Article  MATH  Google Scholar 

  2. Corbin, J. and Bidoit, M. “A Rehabilitation of Robinson’s Unification Algorithm,Information Processing 83, (R. Mason ed.), pp. 909–914, September, 1983.

  3. Jaffar, J., “Efficient Unification Over Infinite Terms”,New Generration Computing, Vol. 2, pp. 207–219, 1984.

    Article  Google Scholar 

  4. Lloyd, J. W.,Foundations of Logic Programming, Springer-Verlag, Berlin, 1984.

    MATH  Google Scholar 

  5. Martelli, A. and Montanari, U., “An Efficient Unification Algorithm”,ACM Transactions on Programming Languages and Systems, Vol. 4, No. 2, pp. 239–257, April, 1982.

    Article  Google Scholar 

  6. Mukai, K., “A Unification Algorithm for Infinite Trees,”Proceedings of the International Joint Conference on Artificial Intelligence, Karlsruhe, pp. 547–549, August, 1983.

  7. Paterson, M. and Wegman, M., “Linear Unification”,Journal of Computer and System Sciences, Vol. 16, pp. 158–167, 1978.

    Article  MATH  MathSciNet  Google Scholar 

  8. Robinson, J. A., “A Machine-Oriented Logic Based on the Resolution Principle”,Journal of the Assocation for Computing Machinery, Vol. 12, No. 1, pp. 23–41, January, 1965.

    MATH  Google Scholar 

  9. Robinson, J. A. “Computational logic: the Unification Computation,” inMachine Intelligence, 6 (B. Meltzer and D Michie, eds.), pp. 63–72, 1971.

  10. Vitter, J. S. and Simons, R. A., “New Classes for Parallel Complexity: A Study of Unification and Other Complete Problems in P”, Technical Report,Cs-84-06, Brown University, Rhode Island, 1984.

    Google Scholar 

  11. Yasuura, H. “On Parallel Complexity of Unification”,Proceedings of the International Conference on Fifth Generation Computer Systems, Tokyo, pp. 235–243 1984.

Download references

Author information

Authors and Affiliations

  1. Department of Computer Science, University of Edinburgh, King’s Buildings, EH9 3JZ, Edinburgh, Scotland

    James Harland

  2. IBM Thomas J. Watson Research Center, P. O. Box 218, 10598, Yorktown Heights, New York, U.S.A.

    Joxan Jaffar

Authors
  1. James Harland
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Joxan Jaffar
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

This research was done at the Department of Computer Science, Monash University, Clayton, Victoria 3168, Australia, and partially supported by the Department of Science through the Machine Intelligence Project

About this article

Cite this article

Harland, J., Jaffar, J. On parallel unification for Prolog. New Gener Comput 5, 259–279 (1987). https://doi.org/10.1007/BF03037466

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF03037466

Keywords

Search

Navigation