Abstract
We implement an online judge for context-free grammars. Our system contains a list of problems describing formal languages, and asking for grammars generating them. A submitted proposal grammar receives a verdict of acceptance or rejection depending on whether the judge determines that it is equivalent to the reference solution grammar provided by the problem setter. Since equivalence of context-free grammars is an undecidable problem, we consider a maximum length ℓ and only test equivalence of the generated languages up to words of length ℓ. This length restriction is very often sufficient for the well-meant submissions. Since this restricted problem is still NP-complete, we design and implement methods based on hashing, SAT, and automata that perform well in practice.
The authors were supported by an FPU grant (first author) and the FORMALISM project (TIN2007-66523) from the Spanish Ministry of Education and Science.
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References
Agarwal, A.: edX (2012), https://www.edx.org
Alexandrova, S., Balandin, A., Compeau, P., Kladov, A., Rayko, M., Sosa, E., Vyahhi, N., Dvorkin, M.: Rosalind (2012), http://www.rosalind.info
Axelsson, R., Heljanko, K., Lange, M.: Analyzing context-free grammars using an incremental SAT solver. In: Aceto, L., Damgård, I., Goldberg, L.A., Halldórsson, M.M., Ingólfsdóttir, A., Walukiewicz, I. (eds.) ICALP 2008, Part II. LNCS, vol. 5126, pp. 410–422. Springer, Heidelberg (2008)
Biere, A.: PicoSAT essentials. Journal on Satisfiability, Boolean Modeling and Computation 4(2-4), 75–97 (2008)
Eén, N., Sörensson, N.: An extensible SAT-solver. In: Giunchiglia, E., Tacchella, A. (eds.) SAT 2003. LNCS, vol. 2919, pp. 502–518. Springer, Heidelberg (2004)
Ganesh, V., Kieżun, A., Artzi, S., Guo, P.J., Hooimeijer, P., Ernst, M.: HAMPI: A string solver for testing, analysis and vulnerability detection. In: Gopalakrishnan, G., Qadeer, S. (eds.) CAV 2011. LNCS, vol. 6806, pp. 1–19. Springer, Heidelberg (2011)
García, C., Revilla, M.A.: UVa online judge (1997), http://uva.onlinejudge.org
Hooker, J.N.: Solving the incremental satisfiability problem. Journal of Logic Programming 15(1&2), 177–186 (1993)
Hopcroft, J.E., Motwani, R., Ullman, J.D.: Introduction to Automata Theory, Languages, and Computation, 3rd edn. Addison-Wesley (2006)
Khan, S.: Khan Academy (2006), https://www.khanacademy.org
Knuth, D.E.: The Art of Computer Programming, vol. III: Sorting and Searching. Addison-Wesley (1973)
Moskewicz, M.W., Madigan, C.F., Zhao, Y., Zhang, L., Malik, S.: Chaff: Engineering an efficient SAT solver. In: Annual ACM IEEE Design Automation Conference, pp. 530–535. ACM (2001)
Ng, A., Koller, D.: Coursera (2012), https://www.coursera.org
Petit, J., Giménez, O., Roura, S.: Jutge.org: an educational programming judge. In: ACM Special Interest Group on Computer Science Education, pp. 445–450 (2012)
Thrun, S., Stavens, D., Sokolsky, M.: Udacity (2012), https://www.udacity.com
Whittemore, J., Kim, J., Sakallah, K.A.: SATIRE: A new incremental satisfiability engine. In: Design Automation Conference, pp. 542–545 (2001)
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Creus, C., Godoy, G. (2014). Automatic Evaluation of Context-Free Grammars (System Description). In: Dowek, G. (eds) Rewriting and Typed Lambda Calculi. RTA TLCA 2014 2014. Lecture Notes in Computer Science, vol 8560. Springer, Cham. https://doi.org/10.1007/978-3-319-08918-8_10
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DOI: https://doi.org/10.1007/978-3-319-08918-8_10
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