Automated Termination Analysis for Logic Programs with Cut

Termination is an important and well-studied property for logic programs. However, almost all approaches for automated termination analysis focus on definite logic programs, whereas real-world Prolog programs typically use the cut operator. We introduce a novel pre-processing method which automatically transforms Prolog programs into logic programs without cuts, where termination of the cut-free program implies termination of the original program. Hence after this pre-processing, any technique for proving termination of definite logic programs can be applied. We implemented this pre-processing in our termination prover AProVE and evaluated it successfully with extensive experiments

Financial market development and financial regulation in the shadow of intensive competition. Ongoing market and policy failure through Basel-III

Die Arbeit entwickelt den Wettbewerb als eine analytische Problemkategorie der Steuerungsforschung. Für zukünftige problemorientierte Steuerungsanalysen wird eine dreifache Regime-Differenzierung vorgeschlagen. Wettbewerbsintensität wird als die zentrale Ursache für die Finanzkrise von 2008 ausgemacht. Sie führte im Zusammenspiel mit dem Basler Eigenkapitalschutz-Regime zu einer Ausbeutung des Problementstehungs-Regimes, den globalen Interbankenmärkten der Finanzierungs- und Risikosteuerung. Die anvisierte Lösung des Problems im Baseler Regelsetzungs-Regime, Basel-III genannt, wird in der Arbeit einer Bewertung unterzogen. Das Ergebnis der Analyse ist, dass die zur Problemlösung eingesetzten Steuerungsinstrumente nicht ursachenadäquat sind. Allerdings wird festgestellt, dass auch dies ein Problem der Wettbewerbsintensität im Baseler Regelsetzungs-Regime ist, in dem Staaten vor dem Hintergrund unterschiedlicher Rechtstraditionen um die Wettbewerbsfähigkeit ihrer Standorte konkurrieren

Gewaltbilder in den Medien: Vertretbar oder verwerflich? Argumentation in der Wissenschaft, unter Journalisten und beim Deutschen Presserat

Täglich erreichen Gewaltbilder aus der ganzen Welt die Redaktionen. Als Gatekeeper müssen Journalisten abwägen: Können, sollen, dürfen oder müssen wir diese Bilder zeigen? Entscheiden sie sich für die Publikation, wird ihnen schnell Sensationsgier unterstellt. Jedoch verlangt der journalistische Auftrag, auch in Bildern über Gewalt, Leid und Tod zu berichten. Die Journalisten stehen vor einem bildethischen Dilemma. Der Beitrag nimmt sich dieser Problematik an und fragt, welche Argumente für und gegen die Veröffentlichung von Gewaltbildern in den Massenmedien sprechen. Betrachtet wird dazu der bildethische Diskurs in der Kommunikationswissenschaft, unter Journalisten und beim Deutschen Presserat. In einem kurzen Exkurs wird auch die Haltung der (katholischen) Kirche eingegangen. Es wird deutlich, dass Kontext und Funktion von Gewaltbildern als entscheidende Faktoren für die moralische Angemessenheit der Publikation gelten. Dabei zeichnet sich ein Argumentationsmuster ab: Die Pro-Argumente berufen sich auf den gesellschaftlichen Wert von Gewaltbildern, die Contra-Argumente pochen mit Blick auf die Abgebildeten, deren Angehörige und Rezipienten auf den Schutz des Individuums. EnglishChristian Ströder/Nikolaus Jackob: Violent Images in the Media: Acceptable or Reprehensible? Argumentation in the Communication Sciences, between Journalists and at the German Press CouncilViolent images from across the entire world arrive daily at editorial offices. As gatekeepers, journalists must consider: Can, should, may we or must we publish these pictures? If they decide for publication they are quickly accused of sensationalism. However, the journalistic mandate also requires that violence, suffering and death be reported upon using pictures. Journalists are confronted with a pictorial-ethical dilemma. The following contribution addresses this issue and questions the arguments which speak for and against the publication of violent images by the mass media. Thereto, the pictorial-ethical dialogue within the communication sciences is considered, between journalists and at the German Press Council. In a short excursus the position of the (Catholic) Church is also looked into. It becomes clear, that for the moral acceptability of their publication the context and function of violent images apply as decisive factors. Thereby, a pattern of argumentation stands out: the pro arguments claim the societal value of violent images while the contra arguments insist in view of the depicted, their immediate family and users, on the protection of the individual

Reversible Computations in Logic Programming

[EN] In this work, we say that a computation is reversible if one can find a procedure to undo the steps of a standard (or forward) computation in a deterministic way. While logic programs are often invertible (e.g., one can use the same predicate for adding and for subtracting natural numbers), computations are not reversible in the above sense. In this paper, we present a so-called Landauer embedding for SLD resolution, the operational principle of logic programs, so that it becomes reversible. A proof-of-concept implementation of a reversible debugger for Prolog that follows the ideas in this paper has been developed and is publicly available.This work is partially supported by the EU (FEDER) and the Spanish MCI/AEI under grants TIN2016-76843-C4-1-R/PID2019-104735RB-C41, by the Generalitat Valenciana under grant Prometeo/2019/098 (DeepTrust), and by the COST Action IC1405 on Reversible Computation - extending horizons of computing.Vidal, G. (2020). Reversible Computations in Logic Programming. Springer. 246-254. https://doi.org/10.1007/978-3-030-52482-1_15S246254Apt, K.: From Logic Programming to Prolog. Prentice Hall, Upper Saddle River (1997)Ducassé, M.: Opium: an extendable trace analyzer for prolog. J. Log. Program. 39(1–3), 177–223 (1999). https://doi.org/10.1016/S0743-1066(98)10036-5Landauer, R.: Irreversibility and heat generation in the computing process. IBM J. Res. Dev. 5, 183–191 (1961)Lanese, I., Palacios, A., Vidal, G.: Causal-consistent replay debugging for message passing programs. In: Pérez, J.A., Yoshida, N. (eds.) FORTE 2019. LNCS, vol. 11535, pp. 167–184. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-21759-4_10Lloyd, J.: Foundations of Logic Programming, 2nd edn. Springer, Berlin (1987). https://doi.org/10.1007/978-3-642-83189-8O’Callahan, R., Jones, C., Froyd, N., Huey, K., Noll, A., Partush, N.: Engineering record and replay for deployability: Extended technical report (2017). CoRR abs/1705.05937, http://arxiv.org/abs/1705.05937Ströder, T., Emmes, F., Schneider-Kamp, P., Giesl, J., Fuhs, C.: A linear operational semantics for termination and complexity analysis of ISO prolog. In: Vidal, G. (ed.) LOPSTR 2011. LNCS, vol. 7225, pp. 237–252. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-32211-2_16Undo Software: Increasing software development productivity with reversible debugging (2014). https://undo.io/media/uploads/files/Undo_ReversibleDebugging_Whitepaper.pd

Concolic Testing in Logic programming

Software testing is one of the most popular validation techniques in the software industry. Surprisingly, we can only find a few approaches to testing in the context of logic programming. In this paper, we introduce a systematic approach for dynamic testing that combines both concrete and symbolic execution. Our approach is fully automatic and guarantees full path coverage when it terminates. We prove some basic properties of our technique and illustrate its practical usefulness through a prototype implementation.This work has been partially supported by the EU (FEDER) and the Spanish Ministerio de Economia y Competitividad under grant TIN2013-44742-C4-1-R and by the Generalitat Valenciana under grant PROMETEOII/2015/013. Part of this research was done while the third author was visiting the University of Reunion; G. Vidal gratefully acknowledges their hospitality.Mesnard, F.; Payet, E.; Vidal Oriola, GF. (2015). Concolic Testing in Logic programming. Theory and Practice of Logic Programming. 15(4):711-725. https://doi.org/10.1017/S1471068415000332S711725154SCHIMPF, J., & SHEN, K. (2011). ECLiPSe – From LP to CLP. Theory and Practice of Logic Programming, 12(1-2), 127-156. doi:10.1017/s1471068411000469Martelli, A., & Montanari, U. (1982). An Efficient Unification Algorithm. ACM Transactions on Programming Languages and Systems, 4(2), 258-282. doi:10.1145/357162.357169Godefroid, P., Klarlund, N., & Sen, K. (2005). DART. Proceedings of the 2005 ACM SIGPLAN conference on Programming language design and implementation - PLDI ’05. doi:10.1145/1065010.1065036Mera E. , López-García P. , and Hermenegildo M. V. 2009. Integrating software testing and run-time checking in an assertion verification framework. In 25th International Conference on Logic Programming, ICLP 2009, Pasadena. 281–295.Godefroid, P., Levin, M. Y., & Molnar, D. (2012). SAGE. Communications of the ACM, 55(3), 40. doi:10.1145/2093548.2093564WIELEMAKER, J., SCHRIJVERS, T., TRISKA, M., & LAGER, T. (2011). SWI-Prolog. Theory and Practice of Logic Programming, 12(1-2), 67-96. doi:10.1017/s1471068411000494CARLSSON, M., & MILDNER, P. (2011). SICStus Prolog—The first 25 years. Theory and Practice of Logic Programming, 12(1-2), 35-66. doi:10.1017/s1471068411000482Degrave F. , Schrijvers T. , and Vanhoof W. 2008. Automatic generation of test inputs for Mercury. In Logic-Based Program Synthesis and Transformation, 18th International Symposium, LOPSTR 2008. 71–86.Somogyi, Z., Henderson, F., & Conway, T. (1996). The execution algorithm of mercury, an efficient purely declarative logic programming language. The Journal of Logic Programming, 29(1-3), 17-64. doi:10.1016/s0743-1066(96)00068-4Vidal, G. (2015). Concolic Execution and Test Case Generation in Prolog. Lecture Notes in Computer Science, 167-181. doi:10.1007/978-3-319-17822-6_10Belli F. and Jack O. 1993. Implementation-based analysis and testing of Prolog programs. In ISSTA. 70–80.King, J. C. (1976). Symbolic execution and program testing. Communications of the ACM, 19(7), 385-394. doi:10.1145/360248.360252Lloyd, J. W. (1987). Foundations of Logic Programming. doi:10.1007/978-3-642-83189-8Clarke L. 1976. A program testing system. In Proceedings of the 1976 Annual Conference (ACM'76). 488–491

An SMT-Based Concolic Testing Tool for Logic Programs

[EN] Concolic testing combines symbolic and concrete execution to generate test cases that achieve a good program coverage. Its benefits have been demonstrated for more than 15 years in the case of imperative programs. In this work, we present a concolic-based test generation tool for logic programs which exploits SMT-solving for constraint resolutionThird author is a research associate at FNRS that also supports this work (O05518FRG03). The last author is partially supported by the EU (FEDER) and the Spanish MCI/AEI under grants TIN2016-76843-C4-1-R/PID2019-104735RB-C41 and by the Generalitat Valenciana under grant Prometeo/2019/098 (DeepTrust)Fortz, S.; Mesnard, F.; Payet, E.; Perrouin, G.; Vanhoof, W.; Vidal, G. (2020). An SMT-Based Concolic Testing Tool for Logic Programs. Springer Nature. 215-219. https://doi.org/10.1007/978-3-030-59025-3_13S215219de Moura, L., Bjørner, N.: Z3: an efficient SMT solver. In: Ramakrishnan, C.R., Rehof, J. (eds.) TACAS 2008. LNCS, vol. 4963, pp. 337–340. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-78800-3_24Giantsios, A., Papaspyrou, N., Sagonas, K.: Concolic testing for functional languages. Sci. Comput. Program. 147, 109–134 (2017)Godefroid, P., Klarlund, N., Sen, K.: DART: directed automated random testing. In: Proceedings of PLDI 2005, pp. 213–223. ACM (2005)Mesnard, F., Payet, É., Vidal, G.: Concolic testing in logic programming. TPLP 15(4–5), 711–725 (2015). https://doi.org/10.1017/S1471068415000332Mesnard, F., Payet, É., Vidal, G.: On the completeness of selective unification in concolic testing of logic programs. In: Hermenegildo, M.V., Lopez-Garcia, P. (eds.) LOPSTR 2016. LNCS, vol. 10184, pp. 205–221. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63139-4_12Mesnard, F., Payet, É., Vidal, G.: Selective unification in constraint logic programming. In: Vanhoof, W., Pientka, B. (eds.) PPDP, pp. 115–126. ACM (2017)Mesnard, F., Payet, É., Vidal, G.: Concolic Testing in CLP. CoRR abs/2008.00421 (2020). https://arxiv.org/abs/2008.00421Sen, K., Marinov, D., Agha, G.: CUTE: a concolic unit testing engine for C. In: ESEC/ FSE, pp. 263–272. ACM (2005)Ströder, T., Emmes, F., Schneider-Kamp, P., Giesl, J., Fuhs, C.: A linear operational semantics for termination and complexity analysis of ISO Prolog. In: Vidal, G. (ed.) LOPSTR 2011. LNCS, vol. 7225, pp. 237–252. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-32211-2_16Tikovsky, J.R.: Concolic testing of functional logic programs. In: Seipel, D., Hanus, M., Abreu, S. (eds.) WFLP/WLP/INAP -2017. LNCS (LNAI), vol. 10997, pp. 169–186. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-00801-7_11Vidal, G.: Concolic execution and test case generation in prolog. In: Proietti, M., Seki, H. (eds.) LOPSTR 2014. LNCS, vol. 8981, pp. 167–181. Springer, Cham (2015). https://doi.org/10.1007/978-3-319-17822-6_10Wielemaker, J., Schrijvers, T., Triska, M., Lager, T.: SWI-prolog. TPLP 12(1–2), 67–96 (2012). https://doi.org/10.1017/S147106841100049

Development of an N-1 perfusion medium to intensify seed train operation

Seed train expansion of cells before the final production step is often time-consuming and a major source of process variability. For the intensification of seed train operations there are several opportunities discussed across the biopharma industry today. One of the possibilities is to operate N-1 bioreactors in perfusion mode to shorten timelines and improve bioreactor utilization. In this work, we investigated the influence of using an expansion medium especially designed for N-1 perfusion to gain optimal results in the whole manufacturing campaign. For screening and designing an N-1 perfusion expansion medium, a scale down model which represents a typical production campaign, including the seed train, was established. Expansion medium prototypes were combined with different production media in the final production step, e.g. EX-CELL® Advanced HD Perfusion as medium designed for high-density perfusion, and Cellvento® 4CHO Medium and 4FEED as exemplary fed-batch process. After determining a suitable expansion medium formulation, the prototype was evaluated for solubility and streamlined to ensure a simple hydration and robust supply chain. Afterwards, results were confirmed using a simulated manufacturing process using benchtop bioreactor systems, showing that the positive impact of the expansion medium on the final yield is present both when using perfusion or fed-batch as final production stage. Our results indicate that using the right companion medium in seed train expansion - specifically designed for the purpose - can prepare the cells optimally for the final N-stage and increase productivity while using low CSPRs. Combining these findings with the application of a perfused N-1 step in the manufacturing campaign leads to a great opportunity for the intensification of the whole upstream process

Upstream process intensification using frozen high cell density intermediates

Typical seed train operations start by thawing of a single vial followed by several expansion steps. Reaching sufficient absolute cell numbers for production bioreactor inoculation is time-consuming and reduces plant flexibility. Besides long ramp up times, open cell culture operations are a major source of process variability. High cell density cryopreservation (HCDC) is a method of freezing cells in bags instead of vials and at higher cell densities. This offers the advantage of decoupling expansion and production: both steps can be separated in space and time. Room classification could be decreased due to fully closed processing and reproducibility increased due to a reduction of manual handling steps. Furthermore, these frozen seed train intermediates allow global distribution from a central expansion facility to decentralized global production facilities. Besides from advantages in production, these HCDC bags can be used in process development to ensure equal starting points in experimental setups. In this study, we developed a single-use bag assembly that supports closed filling, freezing, thawing, and inoculation. Before using the bag application, relevant parameters for this process from filling to inoculation were evaluated in vials with different cell lines. We found that the DMSO concentration for optimal freezing must not be higher than 7,5%. Furthermore, direct freezing at -80 °C instead of using a controlled rate freezing method is possible. Maximum concentration of DMSO in cell cultures should not be higher than 0,5 % when cryopreserved cells in bags are used for inoculation. For the idea of seed train intensification, we tested increasing freezing cell densities from 10 to 100 million cells/mL showing comparable growth. Functionality test of this HCDC method in comparison to vials was demonstrated in 4,2 L bioreactors simulating a manufacturing process. Applicability of this cryopreservation technology has been demonstrated using different bioreactors, perfusion systems, and various CHO cell lines

Proving termination of programs automatically with AProVE

AProVE is a system for automatic termination and complexity proofs of Java, C, Haskell, Prolog, and term rewrite systems (TRSs). To analyze programs in high-level languages, AProVE automatically converts them to TRSs. Then, a wide range of techniques is employed to prove termination and to infer complexity bounds for the resulting TRSs. The generated proofs can be exported to check their correctness using automatic certifiers. For use in software construction, we present an AProVE plug-in for the popular Eclipse software development environment

Teaching breast ultrasound skills including core-needle biopsies on a phantom enhances undergraduate student's knowledge and learning satisfaction

Purpose To investigate whether a training program on breast ultrasound skills including core-needle biopsies to undergraduate students can improve medical knowledge and learning satisfaction. Methods Medical students attending mandatory classes at the Medical School of the University of Saarland received a supplemental theoretical and hands-on training program on ultrasound (US) breast screening and on US-guided core-needle biopsy using an agar–agar phantom. Experienced breast specialists and ultrasound examiners served as trainers applying Peyton’s 4-step training approach. The students’ theoretical knowledge and hands-on skills were tested before and after the training program, using a multiple-choice questionnaire (MCQ), the Objective Structured Clinical Examination (OSCE) and a student curriculum evaluation. Results The MCQ results showed a significant increase of the student’s theoretical knowledge (50.2–75.2%, p < 0.001). After the course, the OSCE showed a mean total of 17.3/20 points (86.5%), confirming the practical implementation of the new skills. The student curriculum evaluation in general was very positive. A total of 16/20 questions were rated between 1.2 and 1.7 (very good) and 3 questions were rated as 2.1 (good). Conclusion Undergraduate student’s medical education can be enhanced by teaching breast US skills