Abstract
We describe the concept of an abstract congruence closure and provide equational inference rules for its construction. The length of any maximal derivation using these inference rules for constructing an abstract congruence closure is at most quadratic in the input size. The framework is used to describe the logical aspects of some well-known algorithms for congruence closure. It is also used to obtain an efficient implementation of congruence closure. We present experimental results that illustrate the relative differences in performance of the different algorithms. The notion is extended to handle associative and commutative function symbols, thus providing the concept of an associative-commutative congruence closure. Congruence closure (modulo associativity and commutativity) can be used to construct ground convergent rewrite systems corresponding to a set of ground equations (containing AC symbols).
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Bachmair, L.: Canonical Equational Proofs, Birkhäuser, Boston, 1991.
Bachmair, L. and Dershowitz, N.: Completion for rewriting modulo a congruence, Theoret. Comput. Sci. 67(2 & 3) (Oct. 1989), 173-201.
Bachmair, L. and Dershowitz, N.: Equational inference, canonical proofs, and proof orderings, J. ACM 41 (1994), 236-276.
Bachmair, L., Ramakrishnan, I., Tiwari, A. and Vigneron, L.: Congruence closure modulo Associativity-Commutativity, in H. Kirchner and C. Ringeissen (eds), Frontiers of Combining Systems, Third International Workshop, FroCoS 2000, Nancy, France, March 2000, Lecture Notes in Artificial Intelligence 1794, Springer, Berlin, 2000, pp. 245-259.
Bachmair, L. and Tiwari, A.: Abstract congruence closure and specializations, in D. McAllester (ed.), Conference on Automated Deduction, CADE 2000, Pittsburgh, PA, June2000, Lecture Notes in Artificial Intelligence 1831, Springer, Berlin, 2000, pp. 64-78.
Bachmair, L. and Tiwari, A.: Congruence closure and syntactic unification, in C. Lynch and D. Narendran (eds), 14th International Workshop on Unification, 2000.
Ballantyne, A. M. and Lankford, D. S.: New decision algorithms for finitely presented commutative semigroups, Comp. Math. Appl. 7 (1981), 159-165.
Becker, T. and Weispfenning, V.: Gröbner Bases: A computational Approach to Commutative Algebra, Springer-Verlag, Berlin, 1993.
Cardozo, E., Lipton, R. and Meyer, A.: Exponential space complete problems for petri nets and commutative semigroups, in Proc. 8th Ann. ACM Symp on Theory of Computing, 1976, pp. 50-54.
Comon, H., Dauchet, M., Gilleron, R., Jacquemard, F., Lugiez, D., Tison, S. and Tommasi, M.: Tree automata techniques and applications. Available on: http://www.grappa.univ-lille3.fr/tata, 1997.
Cyrluk, D., Lincoln, P. and Shankar, N.: On Shostak’s decision procedure for combination of theories, in M. A. McRobbie and J. Slaney (eds), Proceedings of the 13th Int. Conference on Automated Deduction, Lecture Notes in Comput. Sci. 1104, Springer, Berlin, 1996, pp. 463-477.
Dershowitz, N. and Jouannaud, J. P.: Rewrite systems, in J. van Leeuwen (ed.), Handbook of Theoretical Computer Science (Vol. B: Formal Models and Semantics), North-Holland, Amsterdam, 1990.
Dershowitz, N. and Manna, Z.: Proving termination with multiset orderings, Comm. ACM 22(8) (1979), 465-476.
Domenjoud, E. and Klay, F.: Shallow AC theories, in Proceedings of the 2nd CCL Workshop, La Escala, Spain, Sept. 1993.
Downey, P. J., Sethi, R. and Tarjan, R. E.: Variations on the common subexpressions problem, J. ACM 27(4) (1980), 758-771.
Evans, T.: The word problem for abstract algebras, J. London Math. Soc. 26 (1951), 64-71.
Evans, T.: Word problems, Bull. Amer. Math. Soc. 84(5) (1978), 789-802.
Kapur, D.: Shostak’s congruence closure as completion, in H. Comon (ed.), Rewriting Techniques and Applications, RTA 1997, Sitges, Spain, July 1997, Lecture Notes in Comput. Sci. 1103, Springer, Berlin, pp. 23-37.
Koppenhagen, U. and Mayr, E.W.: An optimal algorithm for constructing the reduced Gröbner basis of binomial ideals, in Y. D. Lakshman (ed.), Proceedings of the International Symposium on Symbolic and Algebraic Computation, 1996, pp. 55-62.
Marche, C.: On ground AC-completion, in R. V. Book (ed.), 4th International Conference on Rewriting Techniques and Applications, Lecture Notes in Comput. Sci. 488, Springer, Berlin, 1991, pp. 411-422.
Mayr, E. W. and Meyer, A. R.: The complexity of the word problems for commutative semigroups and polynomial ideals, Adv. in Math. 46 (1982), 305-329.
Narendran, P. and Rusinowitch, M.: Any ground associative-commutative theory has a finite canonical system, in R. V. Book (ed.), 4th International Conference on Rewriting Techniques and Applications, Lecture Notes in Comput. Sci. 488, Springer, Berlin, 1991, pp. 423-434.
Nelson, G. and Oppen, D.: Fast decision procedures based on congruence closure, J. Assoc. Comput. Mach. 27(2) (Apr. 1980), 356-364.
Peterson, G. E. and Stickel, M. E.: Complete sets of reductions for some equational theories, J. ACM 28(2) (Apr. 1981), 233-264.
Plaisted, D. and Sattler-Klein, A.: Proof lengths for equational completion, Inform. and Comput. 125 (1996), 154-170.
Rubio, A. and Nieuwenhuis, R.: A precedence-based total AC-compatible ordering, in C. Kirchner (ed.), Proceedings of the 5 Intl. Conference on Rewriting Techniques and Applications, Lecture Notes in Comput. Sci. 960, Springer, Berlin, 1993, pp. 374-388.
Sherman, D. J. and Magnier, N.: Factotum: Automatic and systematic sharing support for systems analyzers, in Proc. TACAS, Lecture Notes in Comput. Sci. 1384, 1998.
Shostak, R. E.: Deciding combinations of theories, J. ACM 31(1) (1984), 1-12.
Snyder, W.: A fast algorithm for generating reduced ground rewriting systems from a set of ground equations, J. Symbolic Comput. 15(7) (1993).
Tiwari, A.: Decision procedures in automated deduction, Ph.D. thesis, State University of New York at Stony Brook, New York, 2000.
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Bachmair, L., Tiwari, A. & Vigneron, L. Abstract Congruence Closure. Journal of Automated Reasoning 31, 129–168 (2003). https://doi.org/10.1023/B:JARS.0000009518.26415.49
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DOI: https://doi.org/10.1023/B:JARS.0000009518.26415.49