Abstract
It is known that a fixed computation rule, such as used in most logic programming systems, does not suffice for normal logic programs. For instance, SLS resolution, which evaluates programs according to the well-founded semantics, makes use of an oracle to determine the next literal to select in [5], and of ideal parallelism in [8]. Given these limits, it is natural to define a subclass of normal programs for which a fixed computation rule is adequate. This class, left-to-right dynamically stratified programs, properly includes other stratification classes.
Left-to-right dynamically stratified programs are of interest because they are posited to be amenable to efficient implementation. We demonstrate that this is in fact the case with an implementation based on the SLG-WAM of XSB [10]. The SLG-WAM is an extension to the underlying implementation model of Prolog, the WAM, and has been shown to be extremely efficient for definite programs [13]. We show that extending the engine for left-to-right dynamically stratified programs does not slow down execution for definite programs or for Prolog-style SLD evaluation. Indeed, implementation of stratification leads to the technique of early completion which can also benefit definite programs.
This is a preview of subscription content, log in via an institution to check access.
Preview
Unable to display preview. Download preview PDF.
References
K. Apt, H. Blair, and A. Walker. Towards a Theory of Declarative Knowledge. In Foundations of Deductive Databases and Logic Programming, pages 89–148, 1988.
W. Chen, T. Swift, and D. S. Warren. Efficient top-down computation of queries under the well-founded semantics. JLP, 24(3):161–199, 1995.
W. Chen and D. S. Warren. Tabled Evaluation with Delaying for General Logic Programs. JACM. To appear.
H. Przymusinska and T. C. Przymusinski. Weakly stratified logic programs. Fundamenta Informaticae, 13(1):51–65, 1990.
T. C. Przymusinski. Every logic program has a natural stratification and an iterated least fixed point model. In Proceedings of 8th PODS, pages 11–21, 1989.
I. V. Ramakrishnan, P. Rao, K. Sagonas, T. Swift, and D. S. Warren. Efficient tabling mechanisms for logic programs. In ICLP, pages 687–711, 1995. MIT Press.
R. Ramakrishnan, D. Srivastava, and S. Sudarshan. Controlling the search in bottom-up evaluation. In Proceedings of JICSLP, pages 273–287, 1992. MIT Press.
K. A. Ross. A procedural semantics for well-founded negation in logic programs. JLP, 13(1):1–22, 1992.
K. A. Ross. Modular Stratification and Magic Sets for Datalog programs with Negation. JACM, 41(6):1216–1266, 1994.
K. Sagonas, T. Swift, and D. S. Warren. XSB as an efficient deductive database engine. In Proceedings of the ACM SIGMOD Conference, pages 442–453, 1994.
K. Sagonas, T. Swift, and D. S. Warren. The Limits of Fixed-Order Computation. Submitted for publication, 1996.
P. J. Stuckey and S. Sudarshan. Well-Founded Ordered Search. In Proceedings of 13th Conference on FST-TCS, LNCS, pages 161–171, 1993. Springer-Verlag.
T. Swift and D. S. Warren. An abstract machine for SLG resolution: Definite Programs. In Proceedings of the 1994 UPS, pages 633–652, 1994. MIT Press.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1996 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Sagonas, K., Swift, T., Warren, D.S. (1996). An abstract machine for fixed-order dynamically stratified programs. In: McRobbie, M.A., Slaney, J.K. (eds) Automated Deduction — Cade-13. CADE 1996. Lecture Notes in Computer Science, vol 1104. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-61511-3_98
Download citation
DOI: https://doi.org/10.1007/3-540-61511-3_98
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-61511-8
Online ISBN: 978-3-540-68687-3
eBook Packages: Springer Book Archive