Abstract
Conditional rewriting is universally recognized as being much more complicated than unconditional rewriting. In this paper we study how much of conditional rewriting can be automatically inferred from the simpler theory of unconditional rewriting. We introduce a new tool, called unraveling, to automatically translate a conditional term rewriting system (CTRS) into a term rewriting system (TRS). An unraveling enables to infer properties of a CTRS by studying the corresponding ultra-properties using the corresponding TRS. We show how to rediscover properties like decreasingness, and to give nice proofs of some existing results on CTRSs. Moreover, we show how unravelings provide a valuable tool to study modularity of CTRSs, automatically giving a multitude of new results.
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J.A. Bergstra and J.W. Klop. Conditional rewrite rules: Confluence and termination. Journal of Computer and System Sciences, 32(3):323–362, 1986.
N. Dershowitz. Hierarchical termination. In Proceedings 4th International Workshop on Conditional and Typed Rewriting Systems, volume 968 of LNCS, Springer-Verlag, 1995.
N. Dershowitz and J.-P. Jouannaud. Rewrite systems. In J. van Leeuwen, editor, Handbook of Theoretical Computer Science, vol. B, ch. 6, pp. 243–320. Elsevier, 1990.
N. Dershowitz and M. Okada. A rationale for conditional equational programming. Theoretical Computer Science, 75:111–138, 1990.
N. Dershowitz, M. Okada, and G. Sivakumar. Canonical conditional rewrite systems. In Proceedings of the 9th CADE, volume 310 of LNCS, pages 538–549. Springer-Verlag, 1988.
E. Giovannetti and C. Moiso. Notes on the elimination of conditions. In Proceedings 1st International Workshop on Conditional and Typed Rewriting Systems, volume 308 of LNCS, pages 91–97. Springer-Verlag, 1988.
B. Gramlich. Relating innermost, weak, uniform and modular termination of term rewriting systems. In Proc. LPAR, vol. 624 of LNAI, pages 285–296. Springer-Verlag, 1992.
B. Gramlich. Sufficient conditions for modular termination of conditional term rewriting systems. In Third International Workshop on Conditional Term Rewriting Systems, volume 656 of LNCS, pages 128–142. Springer-Verlag, 1993.
B. Gramlich. Generalized sufficient conditions for modular termination of rewriting. Applicable Algebra in Engineering, Communication and Computing, 5:131–158, 1994.
B. Gramlich. On modularity of termination and confluence properties of conditional rewrite systems. In 4th Int. Conf. on Algebraic and Logic Programming, volume 850 of LNCS, pages 186–203. Springer-Verlag, 1994.
C. Hintermeier. How to transform canonical decreasing CTRSs into equivalent canonical TRSs. In Proceedings 4th International Workshop on Conditional and Typed Rewriting Systems, volume 968 of LNCS, pages 186–205. Springer-Verlag, 1995.
J.-P. Jouannaud and B. Waldmann. Reductive conditional term rewrite systems. In 3rd IFIP Working Conference on Formal Description of Programming Concepts, pages 223–244, Ebberup, Denmark, 1986.
S. Kaplan. Conditional rewrite rules. Theoretical Computer Science, 33(2):175–193, 1984.
S. Kaplan. Simplifying conditional term rewriting systems. JSC, 4(3):295–334, 1987.
J.W. Klop. Term rewriting systems. In S. Abramsky, Dov M. Gabbay, and T.S.E. Maibaum, editors, Handbook of Logic in Computer Science, volume 2, chapter 1, pages 1–116. Clarendon Press, Oxford, 1992.
M. Kurihara and A. Ohuchi. Modularity of simple termination of term rewriting systems. Journal of IPS Japan, 31(5):633–642, 1990.
M. Marchiori. Bubbles in modularity. Technical Report 5, Dept. of Pure and Applied Mathematics, University of Padova, 1995. Submitted to TCS.
M. Marchiori. Unravelings and ultra-properties. Technical Report 8, Dept. of Pure and Applied Mathematics, University of Padova, 1995.
M. Marchiori. On the modularity of normal forms in rewriting. J. of Symbolic Computation, 1996. In press. Also available as Tech. Rep. CS-R9433, CWI, Amsterdam, 1994.
A. Middeldorp. A sufficient condition for the termination of the direct sum of term rewriting systems. In Proc. 4th IEEE LICS, pages 396–401, 1989.
A. Middeldorp. Modular properties of conditional term rewriting systems. Information and Computation, 104(1):110–158, 1993.
A. Middeldorp and E. Hamoen. Completeness results for basic narrowing. Applicable Algebra in Engineering, Communication and Computing, 5:213–253, 1994.
E. Ohlebusch. Combinations of simplifying conditional term rewriting systems. In Proceedings 3rd International Workshop on Conditional and Typed Rewriting Systems, volume 656 of LNCS, pages 113–127. Springer-Verlag, 1993.
E. Ohlebusch. On the modularity of termination of term rewriting systems. Theoretical Computer Science, 136(2):333–360, 1994.
E. Ohlebusch. Modular properties of composable term rewriting systems. Journal of Symbolic Computation, 20(1):1–41, 1995.
K. Rao. Completeness of hierarchical combinations of term rewriting systems. In Proc. 13th FST&TCS, volume 761 of LNCS, pages 125–139. Springer-Verlag, 1993.
K. Rao. Simple termination of hierarchical combinations of term rewriting systems. In Proc. TACS, volume 789 of LNCS, pages 203–223. Springer-Verlag, 1994.
K.-C. Raoult and J. Vuillemin. Operational and semantic equivalence between recursive programs. Journal of the ACM, 27(4):772–796, 1980.
M. Rusinowitch. On termination of the direct sum of term rewriting systems. Information Processing Letters, 26:65–70, 1987.
M. Schmidt-Schauß. Unification in a combination of arbitrary disjoint equational theories. Journal of Symbolic Computation, 8(1,2):51–99, 1989.
M. Schmidt-Schauß, M. Marchiori, and S.E. Panitz. Modular termination of r-consistent and left-linear term rewriting systems. TCS, 149(2):361–374, 1995.
R.M. Verma. Unique normal forms and confluence of rewrite systems: Persistence. In Proc. 14th IJCAI, volume 1, pages 362–368, 1995.
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Marchiori, M. (1996). Unravelings and ultra-properties. In: Hanus, M., RodrÃguez-Artalejo, M. (eds) Algebraic and Logic Programming. ALP 1996. Lecture Notes in Computer Science, vol 1139. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-61735-3_7
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DOI: https://doi.org/10.1007/3-540-61735-3_7
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