Debugging of Web Applications with Web-TLR

Web-TLR is a Web verification engine that is based on the well-established Rewriting Logic--Maude/LTLR tandem for Web system specification and model-checking. In Web-TLR, Web applications are expressed as rewrite theories that can be formally verified by using the Maude built-in LTLR model-checker. Whenever a property is refuted, a counterexample trace is delivered that reveals an undesired, erroneous navigation sequence. Unfortunately, the analysis (or even the simple inspection) of such counterexamples may be unfeasible because of the size and complexity of the traces under examination. In this paper, we endow Web-TLR with a new Web debugging facility that supports the efficient manipulation of counterexample traces. This facility is based on a backward trace-slicing technique for rewriting logic theories that allows the pieces of information that we are interested to be traced back through inverse rewrite sequences. The slicing process drastically simplifies the computation trace by dropping useless data that do not influence the final result. By using this facility, the Web engineer can focus on the relevant fragments of the failing application, which greatly reduces the manual debugging effort and also decreases the number of iterative verifications.Comment: In Proceedings WWV 2011, arXiv:1108.208

Exploring Conditional Rewriting Logic Computations

[EN] Trace exploration is concerned with techniques that allow computation traces to be dynamically searched for specific contents. Depending on whether the exploration is carried backward or forward, trace exploration techniques allow provenance tracking or impact tracking to be done. The aim of provenance tracking is to show how (parts of) a program output depends on (parts of) its input and to help estimate which input data need to be modified to accomplish a change in the outcome. The aim of impact tracking is to identify the scope and potential consequences of changing the program input. Rewriting Logic (RWL) is a logic of change that supplements (an extension of) the equational logic by adding rewrite rules that are used to describe (nondeterministic) transitions between states. In this paper, we present a rich and highly dynamic, parameterized technique for the forward inspection of RWL computations that allows the nondeterministic execution of a given conditional rewrite theory to be followed up in different ways. With this technique, an analyst can browse, slice, filter, or search the traces as they come to life during the program execution. The navigation of the trace is driven by a user-defined, inspection criterion that specifies the required exploration mode. By selecting different inspection criteria, one can automatically derive a family of practical algorithms such as program steppers and more sophisticatedThis work has been partially supported by the EU (FEDER) and the Spanish MEC project Ref. TIN2010-21062-C02-02, the Spanish MICINN complementary action Ref. TIN2009-07495-E, and by Generalitat Valenciana Ref. PROMETEO2011/052. This work was carried out during the tenure of D. Ballis' ERCIM "Alain Bensoussan" Postdoctoral Fellowship. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement N. 246016. F. Frechina was supported by FPU-ME grant AP2010-5681, and J. Sapina was supported by FPI-UPV grant SP2013-0083.Alpuente Frasnedo, M.; Ballis, D.; Frechina Navarro, F.; Sapiña Sanchis, J. (2015). Exploring Conditional Rewriting Logic Computations. Journal of Symbolic Computation. 69:3-39. https://doi.org/10.1016/j.jsc.2014.09.028S3396

Inferring Safe Maude Programs with \uc1TAME

In this paper, we present \atame, an assertion-based program specialization tool for the multi-paradigm language Maude. The program specializer \atame\ takes as input a set \cA of system assertions that model the expected program behavior plus a Maude program \cR to be specialized that might violate some of the assertions in \cA. The outcome of the tool is a safe program refinement \cR' of \cR in which every computation is a good run, i.e., it satisfies the assertions in \cA. The specialization technique encoded in \atame\ is fully automatic and ensures that no good run of \cR is removed from \cR', while the number of bad runs is reduced to zero. We demonstrate the tool capabilities by specializing an overly general nondeterministic dam controller to fulfill a safety policy given by a set of system assertions

Slicing-Based Trace Analysis of Rewriting Logic Specifications with i Julienne

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-37036-6_7We present iJulienne, a trace analyzer for conditional rewriting logic theories that can be used to compute abstract views of Maude executions that help users understand and debug programs. Given a Maude execution trace and a slicing criterion which consists of a set of target symbols occurring in a selected state of the trace, iJulienne is able to track back reverse dependences and causality along the trace in order to incrementally generate highly reduced program and trace slices that reconstruct all and only those pieces of information that are needed to deliver the symbols of interest. iJulienne is also endowed with a trace querying mechanism that increases flexibility and reduction power and allows program runs to be examined at the appropriate level of abstraction.This work has been partially supported by the EU (FEDER) and the Spanish MEC project ref. TIN2010-21062-C02-02, and Generalitat Valenciana ref. PROMETEO2011/052, and was carried out during the tenure of D. Ballis’ ERCIM ”Alain Bensoussan” Postdoctoral Fellowship. The research leading to these results has received funding from the EU 7th Framework Programme (FP7/2007-2013) under agreement n. 246016. F. Frechina is supported by FPU-ME grant AP2010-5681.Alpuente Frasnedo, M.; Ballis, D.; Frechina, F.; Sapiña Sanchis, J. (2013). Slicing-Based Trace Analysis of Rewriting Logic Specifications with iJulienne. En Programming Languages and Systems. Springer. 121-124. https://doi.org/10.1007/978-3-642-37036-6_7S121124Alpuente, M., Ballis, D., Espert, J., Romero, D.: Model-Checking Web Applications with Web-TLR. In: Bouajjani, A., Chin, W.-N. (eds.) ATVA 2010. LNCS, vol. 6252, pp. 341–346. Springer, Heidelberg (2010)Alpuente, M., Ballis, D., Espert, J., Romero, D.: Backward Trace Slicing for Rewriting Logic Theories. In: Bjørner, N., Sofronie-Stokkermans, V. (eds.) CADE 2011. LNCS, vol. 6803, pp. 34–48. Springer, Heidelberg (2011)Alpuente, M., Ballis, D., Frechina, F., Romero, D.: Backward Trace Slicing for Conditional Rewrite Theories. In: Bjørner, N., Voronkov, A. (eds.) LPAR-18 2012. LNCS, vol. 7180, pp. 62–76. Springer, Heidelberg (2012)Alpuente, M., Ballis, D., Frechina, F., Romero, D.: Julienne: A Trace Slicer for Conditional Rewrite Theories. In: Giannakopoulou, D., Méry, D. (eds.) FM 2012. LNCS, vol. 7436, pp. 28–32. Springer, Heidelberg (2012)Alpuente, M., Ballis, D., Frechina, F., Romero, D.: Using Conditional Trace Slicing for Improving Maude Programs. Science of Comp. Progr. (to appear, 2013)The i julienne website (2013), http://safe-tools.dsic.upv.es/iJulienneKorel, B., Laski, J.: Dynamic Program Slicing. Inf. Process. Lett. 29(3), 155–163 (1988

ACUOS: A System for Modular ACU Generalization with Subtyping and Inheritance

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-11558-0_40Computing generalizers is relevant in a wide spectrum of automated reasoning areas where analogical reasoning and inductive inference are needed. The ACUOS system computes a complete and minimal set of semantic generalizers (also called “anti-unifiers”) of two structures in a typed language modulo a set of equational axioms. By supporting types and any (modular) combination of associativity (A), commutativity (C), and unity (U) algebraic axioms for function symbols, ACUOS allows reasoning about typed data structures, e.g. lists, trees, and (multi-)sets, and typical hierarchical/structural relations such as is a and part of. This paper discusses the modular ACU generalization tool ACUOS and illustrates its use in a classical artificial intelligence problem.This work has been partially supported by the EU (FEDER) and the Spanish MINECO under grants TIN 2010-21062-C02-02 and TIN 2013-45732-C4-1-P, by Generalitat Valenciana PROMETEO2011/052, and by NSF Grant CNS 13-10109. J. Espert has also been supported by the Spanish FPU grant FPU12/06223.Alpuente Frasnedo, M.; Escobar Román, S.; Espert Real, J.; Meseguer, J. (2014). ACUOS: A System for Modular ACU Generalization with Subtyping and Inheritance. En Logics in Artificial Intelligence. Springer. 573-581. https://doi.org/10.1007/978-3-319-11558-0_40S573581Alpuente, M., Escobar, S., Espert, J., Meseguer, J.: A Modular Order-sorted Equational Generalization Algorithm. Information and Computation 235, 98–136 (2014)Alpuente, M., Escobar, S., Meseguer, J., Ojeda, P.: A Modular Equational Generalization Algorithm. In: Hanus, M. (ed.) LOPSTR 2008. LNCS, vol. 5438, pp. 24–39. Springer, Heidelberg (2009)Alpuente, M., Escobar, S., Meseguer, J., Ojeda, P.: Order–Sorted Generalization. ENTCS 246, 27–38 (2009)Alpuente, M., Espert, J., Escobar, S., Meseguer, J.: ACUOS: A System for Modular ACU Generalization with Subtyping and Inheritance. Tech. rep., DSIC-UPV (2013), http://www.dsic.upv.es/users/elp/papers.htmlArmengol, E.: Usages of Generalization in Case-Based Reasoning. In: Weber, R.O., Richter, M.M. (eds.) ICCBR 2007. LNCS (LNAI), vol. 4626, pp. 31–45. Springer, Heidelberg (2007)Clavel, M., Durán, F., Eker, S., Lincoln, P., Martí-Oliet, N., Meseguer, J., Talcott, C. (eds.): All About Maude - A High-Performance Logical Framework. LNCS, vol. 4350. Springer, Heidelberg (2007)Clavel, M., Durán, F., Eker, S., Lincoln, P., Martí-Oliet, N., Meseguer, J., Talcott, C.L.: Reflection, metalevel computation, and strategies. In: All About Maude [6], pp. 419–458Gentner, D.: Structure-Mapping: A Theoretical Framework for Analogy*. Cognitive Science 7(2), 155–170 (1983)Krumnack, U., Schwering, A., Gust, H., Kühnberger, K.-U.: Restricted higher order anti unification for analogy making. In: Orgun, M.A., Thornton, J. (eds.) AI 2007. LNCS (LNAI), vol. 4830, pp. 273–282. Springer, Heidelberg (2007)Kutsia, T., Levy, J., Villaret, M.: Anti-Unification for Unranked Terms and Hedges. Journal of Automated Reasoning 520, 155–190 (2014)Meseguer, J.: Conditioned rewriting logic as a united model of concurrency. Theor. Comput. Sci. 96(1), 73–155 (1992)Muggleton, S.: Inductive Logic Programming: Issues, Results and the Challenge of Learning Language in Logic. Artif. Intell. 114(1-2), 283–296 (1999)Ontañón, S., Plaza, E.: Similarity measures over refinement graphs. Machine Learning 87(1), 57–92 (2012)Plotkin, G.: A note on inductive generalization. In: Machine Intelligence, vol. 5, pp. 153–163. Edinburgh University Press (1970)Pottier, L.: Generalisation de termes en theorie equationelle: Cas associatif-commutatif. Tech. Rep. INRIA 1056, Norwegian Computing Center (1989)Schmid, U., Hofmann, M., Bader, F., Häberle, T., Schneider, T.: Incident Mining using Structural Prototypes. In: García-Pedrajas, N., Herrera, F., Fyfe, C., Benítez, J.M., Ali, M. (eds.) IEA/AIE 2010, Part II. LNCS, vol. 6097, pp. 327–336. Springer, Heidelberg (2010

Interactive Simplifier Tracing and Debugging in Isabelle

The Isabelle proof assistant comes equipped with a very powerful tactic for term simplification. While tremendously useful, the results of simplifying a term do not always match the user's expectation: sometimes, the resulting term is not in the form the user expected, or the simplifier fails to apply a rule. We describe a new, interactive tracing facility which offers insight into the hierarchical structure of the simplification with user-defined filtering, memoization and search. The new simplifier trace is integrated into the Isabelle/jEdit Prover IDE.Comment: Conferences on Intelligent Computer Mathematics, 201

Identificación of ERBB4 and SOX1 role in central nervous system tumors. Implication in medulloblastoma and glioblastoma.

223 p.Los tumores cerebrales, como el glioblastoma (GBM) en adultos y el meduloblastoma (MB) en niños, representan uno de los retos más importantes de la medicina actual, ya que resisten a las terapias disponibles, recurren y se diseminan. Dichos tumores presentan una alta heterogeneidad, ya que albergan una subpoblación de células madre tumorales (CSCs), responsables de la metástasis, resistencia a tratamientos y recurrencia tumoral. Además, la desregulación de aquellos genes relacionados con el desarrollo embrionario y el mantenimiento de las células madre, como ERBB4 y SOX1, parece ser crítica para el desarrollo y la progresión del fenotipo canceroso. La presente tesis doctoral tiene como objetivo principal determinar la función de ambos genes en el GBM y el MB, así como establecer su relación con las CSCs específicas de cada tumor (GSCs y MBSCs, respectivamente). En primer lugar, observamos que ERBB4 tiene una función esencial en el desarrollo del cerebelo, controlando la población de las células progenitoras y su proceso de migración. Además, determinamos que ERBB4 se encuentra altamente expresado en los MBs del Grupo 4 y SOX1 en los del Grupo SHH, asociándose en ambos casos a una peor supervivencia. Al inhibir la expresión de ERBB4 y SOX1, observamos una reducción de la viabilidad celular, capacidad de autorrenovación, y de iniciación y progresión tumoral. Asimismo, identificamos un enriquecimiento de la expresión de SOX1 y ERBB4 en las MBSCs. También establecimos una relación entre la elevada expresión de SOX1 y una peor supervivencia en GBM, además del enriquecimiento de su expresión en las GSCs. Por último, al inhibir la expresión de SOX1 en GBM, observamos una disminución de la capacidad de proliferación, iniciación y progresión tumoral. En conjunto, nuestros resultados sugieren un papel oncogénico hasta ahora no descrito de ERBB4 y SOX1 en MB y GBM. Además, este trabajo propone la inhibición de ERBB4 y SOX1 como una estrategia terapéutica prometedora para atacar las CSCs y así combatir la resistencia a las terapias

Guided Unfoldings for Finding Loops in Standard Term Rewriting

In this paper, we reconsider the unfolding-based technique that we have introduced previously for detecting loops in standard term rewriting. We improve it by guiding the unfolding process, using distinguished positions in the rewrite rules. This results in a depth-first computation of the unfoldings, whereas the original technique was breadth-first. We have implemented this new approach in our tool NTI and compared it to the previous one on a bunch of rewrite systems. The results we get are promising (better times, more successful proofs).Comment: Pre-proceedings paper presented at the 28th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2018), Frankfurt am Main, Germany, 4-6 September 2018 (arXiv:1808.03326

Formal methods for industrial critical systems, preface to the special section

[EN] This special issue contains improved versions of selected papers from the workshops on Formal Methods for Industrial Critical Systems (FMICS) held in Eindhoven, The Netherlands, in November 2009 and in Antwerp, Belgium, in September 2010. These were, respectively, the 14th and 15th of a series of international workshops organized by an open working group supported by ERCIM (European Research Consortium for Informatics and Mathematics) that promotes research in all aspects of formal methods (see details in http://www.inrialpes.fr/vasy/fmics/). The FMICS workshops that have produced this special issue considered papers describing original, previously unpublished research and not simultaneously submitted for publication elsewhere, and dealing with the following themes: Design, specification, code generation and testing based on formal methods. Methods, techniques and tools to support automated analysis, certification, debugging, learning, optimization and transformation of complex, distributed, real-time and embedded systems. Verification and validation methods that address shortcomings of existing methods with respect to their industrial applicability (e.g., scalability and usability issues). Tools for the development of formal design descriptions. Case studies and experience reports on industrial applications of formal methods, focusing on lessons learned or new research directions. Impact and costs of the adoption of formal methods. Application of formal methods in standardization and industrial forums. The selected papers are the result of several evaluation steps. In response to the call for papers, FMICS 2009 received 24 papers and FMICS 2010 received 33 papers, with 10 and 14 accepted, respectively, which were published by Springer- Verlag in the series Lecture Notes in Computer Science (volumes 5825 [1] and 6371 [2]). Each paper was reviewed by at least three anonymous referees which provided full written evaluations. After the workshops, the authors of 10 papers were invited to submit extended journal versions to this special issue. These papers passed two review phases, and finally 7 were accepted to be included in the journal.his work has been partially supported by the EU (FEDER) and the Spanish MEC TIN2010-21062-C02-02 project, MICINN INNCORPORA-PTQ program, and by Generalitat Valenciana, ref. PROMETEO2011/052.Alpuente Frasnedo, M.; Joubert ., C.; Kowalewski, S.; Roveri, M. (2013). Formal methods for industrial critical systems, preface to the special section. Science of Computer Programming. 78(7):775-777. doi:10.1016/j.scico.2012.05.005S77577778

Inspecting Maude Variants with GLINTS

[EN] This paper introduces GLINTS, a graphical tool for exploring variant narrowing computations in Maude. The most recent version of Maude, version 2.7.1, provides quite sophisticated unification features, including order-sorted equational unification for convergent theories modulo axioms such as associativity, commutativity, and identity. This novel equational unification relies on built-in generation of the set of variants of a term t, i.e., the canonical form of t sigma for a computed substitution sigma. Variant generation relies on a novel narrowing strategy called folding variant narrowing that opens up new applications in formal reasoning, theorem proving, testing, protocol analysis, and model checking, especially when the theory satisfies the finite variant property, i.e., there is a finite number of most general variants for every term in the theory. However, variant narrowing computations can be extremely involved and are simply presented in text format by Maude, often being too heavy to be debugged or even understood. The GLINTS system provides support for (i) determining whether a given theory satisfies the finite variant property, (ii) thoroughly exploring variant narrowing computations, (iii) automatic checking of node embedding and closedness modulo axioms, and (iv) querying and inspecting selected parts of the variant trees.This work has been partially supported by EU (FEDER) and Spanish MINECO grant TIN 2015-69175-C4-1-R and by Generalitat Valenciana PROMETEO-II/2015/013. Angel Cuenca-Ortega is supported by SENESCYT, Ecuador (scholarship program 2013), and Julia Sapina by FPI-UPV grant SP2013-0083. Santiago Escobar is supported by the Air Force Office of Scientific Research under award number FA9550-17-1-0286.Alpuente Frasnedo, M.; Cuenca-Ortega, A.; Escobar Román, S.; Sapiña-Sanchis, J. (2017). Inspecting Maude Variants with GLINTS. Theory and Practice of Logic Programming. 17(5-6):689-707. https://doi.org/10.1017/S147106841700031XS689707175-