Abstract
Unravelings constitute a class of program transformations to model conditional rewrite systems as standard term rewrite systems. Key properties of unravelings are soundness and completeness with respect to reductions, in the sense that rewrite sequences in the unraveled system correspond to rewrite sequences in the conditional system and vice versa. While the latter is easily satisfied, the former holds only under certain conditions and is notoriously difficult to prove. This paper describes an Isabelle formalization of both properties. The soundness proof is based on the approach by Nishida, Sakai, and Sakabe (2012) but we also contribute to the theory by showing it applicable to a larger class of unravelings.
Based on our formalization we developed the first certifier to check output of conditional rewrite tools. In particular, quasi-decreasingness proofs by AProVE and conditional confluence proofs by ConCon can be certified.
This research was supported by the Austrian Science Fund (FWF) projects I963 and Y757.
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References
Baader, F., Nipkow, T.: Term Rewriting and All That. Cambridge University Press (1998)
DurĂ¡n, F., Lucas, S., Meseguer, J., MarchĂ©, C., Urbain, X.: Proving termination of membership equational programs. In: Proc. PEPM 2004, pp. 147–158 (2004)
Giesl, J., Brockschmidt, M., Emmes, F., Frohn, F., Fuhs, C., Otto, C., PlĂ¼cker, M., Schneider-Kamp, P., Ströder, T., Swiderski, S., Thiemann, R.: Proving termination of programs automatically with AProVE. In: Demri, S., Kapur, D., Weidenbach, C. (eds.) IJCAR 2014. LNCS, vol. 8562, pp. 184–191. Springer, Heidelberg (2014)
Gmeiner, K., Nishida, N., Gramlich, B.: Proving confluence of conditional term rewriting systems via unravelings. In: Proc. IWC 2013, pp. 35–39 (2013)
Gramlich, B.: Abstract relations between restricted termination and confluence properties of rewrite systems. Fundamenta Informaticae 24, 3–23 (1995)
Lucas, S., Marché, C., Meseguer, J.: Operational termination of conditional term rewriting systems. IPL 95(4), 446–453 (2005)
Marchiori, M.: Unravelings and ultra-properties. In: Hanus, M., RodrĂguez-Artalejo, M. (eds.) ALP 1996. LNCS, vol. 1139, pp. 107–121. Springer, Heidelberg (1996)
Marchiori, M.: On deterministic conditional rewriting. Technical Report Computation Structures Group Memo 405. MIT (1997)
Nagele, J., Thiemann, R.: Certification of confluence proofs using. In: Proc. 3rd IWC, pp. 19–23 (2014)
Nipkow, T., Paulson, L.C., Wenzel, M.: Isabelle/HOL. LNCS, vol. 2283. Springer, Heidelberg (2002)
Nishida, N.: Transformational Approach to Inverse Computation in Term Rewriting. PhD thesis, Nagoya University (2004)
Nishida, N., Sakai, M., Sakabe, T.: Soundness of unravelings for conditional term rewriting systems via ultra-properties related to linearity. LMCS 8(3), 1–49 (2012)
Ohlebusch, E.: Transforming conditional rewrite systems with extra variables into unconditional systems. In: Ganzinger, H., McAllester, D., Voronkov, A. (eds.) LPAR 1999. LNCS, vol. 1705, pp. 111–130. Springer, Heidelberg (1999)
Ohlebusch, E.: Termination of logic programs: Transformational methods revisited. AAECC 12(1–2), 73–116 (2001)
Ohlebusch, E.: Advanced Topics in Term Rewriting. Springer (2002)
Ohlebusch, E., Claves, C., Marché, C.: TALP: A tool for the termination analysis of logic programs. In: Bachmair, L. (ed.) RTA 2000. LNCS, vol. 1833, pp. 270–273. Springer, Heidelberg (2000)
Sternagel, T., Middeldorp, A.: Conditional confluence (System description). In: Dowek, G. (ed.) RTA-TLCA 2014. LNCS, vol. 8560, pp. 456–465. Springer, Heidelberg (2014)
Thiemann, R., Sternagel, C.: Certification of termination proofs using. In: Berghofer, S., Nipkow, T., Urban, C., Wenzel, M. (eds.) TPHOLs 2009. LNCS, vol. 5674, pp. 452–468. Springer, Heidelberg (2009)
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Winkler, S., Thiemann, R. (2015). Formalizing Soundness and Completeness of Unravelings. In: Lutz, C., Ranise, S. (eds) Frontiers of Combining Systems. FroCoS 2015. Lecture Notes in Computer Science(), vol 9322. Springer, Cham. https://doi.org/10.1007/978-3-319-24246-0_15
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DOI: https://doi.org/10.1007/978-3-319-24246-0_15
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