[21] Sylvie Boldo, Catherine Lelay, and Guillaume Melquiond. Improving real analysis in Coq: a user-friendly approach to integrals and derivatives. In Chris Hawblitzel and Dale Miller, editors, Proceedings of the Second International Conference on Certified Programs and Proofs, volume 7679 of Lecture Notes in Computer Science, pages 289--304, Kyoto, Japan, December 2012. [ bib | DOI | full text on HAL ]
[20] François Bobot and Jean-Christophe Filliâtre. Separation predicates: a taste of separation logic in first-order logic. In 14th International Conference on Formal Ingineering Methods (ICFEM), volume 7635 of Lecture Notes in Computer Science, Kyoto, Japan, November 2012. Springer. [ bib | full text on HAL | .pdf ]
This paper introduces separation predicates, a technique to reuse some ideas from separation logic in the framework of program verification using a traditional first-order logic. The purpose is to benefit from existing specification languages, verification condition generators, and automated theorem provers. Separation predicates are automatically derived from user-defined inductive predicates. We illustrate this idea on a non-trivial case study, namely the composite pattern, which is specified in C/ACSL and verified in a fully automatic way using SMT solvers Alt-Ergo, CVC3, and Z3.

[19] Vijay Saraswat, David Cunningham, Liana Hadarean, Louis Mandel, Avraham Shinnar, and Olivier Tardieu. Constrained types - future directions. In 18th International Conference on Principles and Practice of Constraint Programming, Québec City, Canada, October 2012. Position Paper. [ bib | full text on HAL | .pdf ]
The use of constraints in types is quite natural. Yet, integrating constraint based types into the heart of a modern, statically typed, object-oriented programming language is quite tricky. Over the last five years we have designed and implemented the constrained types framework in the programming language X10. In this paper we review the conceptual design, the practical implementation issues, and the many new questions that are raised. We expect the pursuit of these questions to be a profitable area of future work.

[18] Mário Pereira, Jean-Christophe Filliâtre, and Simão Melo de Sousa. ARMY: a deductive verification platform for ARM programs using Why3. In INForum 2012, September 2012. [ bib | .pdf ]
Unstructured (low-level) programs tend to be challenging to prove correct, since the control flow is arbitrary complex and there are no obvious points in the code where to insert logical assertions. In this paper, we present a system to formally verify ARM programs, based on a flow sequentialization methodology and a formalized ARM semantics. This system, built upon the why3 verification platform, takes an annotated ARM program, turns it into a set of purely sequential flow programs, translates these programs' instructions into the corresponding formalized opcodes and finally calls the Why3 VCGen to generate the verification conditions that can then be discharged by provers. A prototype has been implemented and used to verify several programming examples.

Keywords: Why3
[17] David Baelde, Pierre Courtieu, David Gross-Amblard, and Christine Paulin-Mohring. Towards Provably Robust Watermarking. In ITP 2012, volume 7406 of Lecture Notes in Computer Science, August 2012. [ bib | full text on HAL | .pdf ]
Watermarking techniques are used to help identifying copies of publicly released information. They consist in applying a slight and secret modification to the data before its release, in a way that should be robust, ie., remain recognizable even in (reasonably) modified copies of the data. In this paper, we present new results about the robustness of watermarking schemes against arbitrary attackers, and the formalization of those results in Coq. We used the ALEA library, which formalizes probability theory and models probabilistic programs using a simple monadic translation. This work illustrates the strengths and particularities of the induced style of reasoning about probabilistic programs. Our technique for proving robustness is adapted from methods commonly used for cryptographic protocols, and we discuss its relevance to the field of watermarking.

Keywords: watermarking, probabilistic algorithms, formal proofs, security, interactive theorem proving
[16] Jean-Christophe Filliâtre. Combining Interactive and Automated Theorem Proving using Why3 (invited tutorial). In Zvonimir Rakamarić, editor, Second International Workshop on Intermediate Verification Languages (BOOGIE 2012), Berkeley, California, USA, July 2012. [ bib ]
[15] Sylvain Conchon, Amit Goel, Sava Krstić, Alain Mebsout, and Fatiha Zaïdi. Cubicle: A parallel SMT-based model checker for parameterized systems. In Madhusudan Parthasarathy and Sanjit A. Seshia, editors, CAV 2012: Proceedings of the 24th International Conference on Computer Aided Verification, volume 7358 of Lecture Notes in Computer Science, Berkeley, California, USA, July 2012. Springer. [ bib | full text on HAL ]
Cubicle is a new model checker for verifying safety properties of parameterized systems. It implements a parallel symbolic backward reachability procedure using Satisfiabilty Modulo Theories. Experiments done on classic and challenging mutual exclusion algorithms and cache coherence protocols show that Cubicle is effective and competitive with state-of-the-art model checkers.

[14] Louis Mandel and Florence Plateau. Scheduling and buffer sizing of n-synchronous systems: Typing of ultimately periodic clocks in Lucy-n. In Eleventh International Conference on Mathematics of Program Construction (MPC'12), Madrid, Spain, June 2012. [ bib | .pdf ]
Lucy-n is a language for programming networks of processes communicating through bounded buffers. A dedicated type system, termed a clock calculus, automatically computes static schedules of the processes and the sizes of the buffers between them.

In this article, we present a new algorithm which solves the subtyping constraints generated by the clock calculus. The advantage of this algorithm is that it finds schedules for tightly coupled systems. Moreover, it does not overestimate the buffer sizes needed and it provides a way to favor either system throughput or buffer size minimization.

[13] David Mentré, Claude Marché, Jean-Christophe Filliâtre, and Masashi Asuka. Discharging proof obligations from Atelier B using multiple automated provers. In Steve Reeves and Elvinia Riccobene, editors, ABZ'2012 - 3rd International Conference on Abstract State Machines, Alloy, B and Z, volume 7316 of Lecture Notes in Computer Science, pages 238--251, Pisa, Italy, June 2012. Springer. http://hal.inria.fr/hal-00681781/en/. [ bib | full text on HAL ]
We present a method to discharge proof obligations from Atelier B using multiple SMT solvers. It is based on a faithful modeling of B's set theory into polymorphic first-order logic. We report on two case studies demonstrating a significant improvement in the ratio of obligations that are automatically discharged.

[12] François Bobot, Sylvain Conchon, Évelyne Contejean, Mohamed Iguernelala, Assia Mahboubi, Alain Mebsout, and Guillaume Melquiond. A Simplex-based extension of Fourier-Motzkin for solving linear integer arithmetic. In Bernhard Gramlich, Dale Miller, and Ulrike Sattler, editors, IJCAR 2012: Proceedings of the 6th International Joint Conference on Automated Reasoning, volume 7364 of Lecture Notes in Computer Science, pages 67--81, Manchester, UK, June 2012. Springer. [ bib | DOI | full text on HAL ]
This paper describes a novel decision procedure for quantifier-free linear integer arithmetic. Standard techniques usually relax the initial problem to the rational domain and then proceed either by projection (e.g. Omega-Test) or by branching/cutting methods (branch-and-bound, branch-and-cut, Gomory cuts). Our approach tries to bridge the gap between the two techniques: it interleaves an exhaustive search for a model with bounds inference. These bounds are computed provided an oracle capable of finding constant positive linear combinations of affine forms. We also show how to design an efficient oracle based on the Simplex procedure. Our algorithm is proved sound, complete, and terminating and is implemented in the Alt-Ergo theorem prover. Experimental results are promising and show that our approach is competitive with state-of-the-art SMT solvers.

[11] Jean-Christophe Filliâtre, Andrei Paskevich, and Aaron Stump. The 2nd verified software competition: Experience report. In Vladimir Klebanov and Sarah Grebing, editors, COMPARE2012: 1st International Workshop on Comparative Empirical Evaluation of Reasoning Systems, Manchester, UK, June 2012. EasyChair. [ bib | full text on HAL | .pdf ]
We report on the second verified software competition. It was organized by the three authors on a 48 hours period on November 8--10, 2011. This paper describes the competition, presents the five problems that were proposed to the participants, and gives an overview of the solutions sent by the 29 teams that entered the competition.

[10] Jean-Christophe Filliâtre. Combining Interactive and Automated Theorem Proving in Why3 (invited talk). In Keijo Heljanko and Hugo Herbelin, editors, Automation in Proof Assistants 2012, Tallinn, Estonia, April 2012. [ bib ]
[9] Catherine Lelay and Guillaume Melquiond. Différentiabilité et intégrabilité en Coq. Application à la formule de d'Alembert. In Vingt-troisièmes Journées Francophones des Langages Applicatifs, Carnac, France, February 2012. [ bib | full text on HAL ]
[8] Paolo Herms, Claude Marché, and Benjamin Monate. A certified multi-prover verification condition generator. In Rajeev Joshi, Peter Müller, and Andreas Podelski, editors, Verified Software: Theories, Tools, Experiments (4th International Conference VSTTE), volume 7152 of Lecture Notes in Computer Science, pages 2--17, Philadelphia, USA, January 2012. Springer. [ bib | full text on HAL | .pdf ]
[7] Jean-Christophe Filliâtre. Verifying two lines of C with Why3: an exercise in program verification. In Rajeev Joshi, Peter Müller, and Andreas Podelski, editors, Verified Software: Theories, Tools, Experiments (4th International Conference VSTTE), volume 7152 of Lecture Notes in Computer Science, pages 83--97, Philadelphia, USA, January 2012. Springer. [ bib | .pdf ]
This article details the formal verification of a 2-line C program that computes the number of solutions to the n-queens problem. The formal proof of (an abstraction of) the C code is performed using the Why3 tool to generate the verification conditions and several provers (Alt-Ergo, CVC3, Coq) to discharge them. The main purpose of this article is to illustrate the use of Why3 in verifying an algorithmically complex program.

Keywords: Why3
[6] Thorsten Bormer, Marc Brockschmidt, Dino Distefano, Gidon Ernst, Jean-Christophe Filliâtre, Radu Grigore, Marieke Huisman, Vladimir Klebanov, Claude Marché, Rosemary Monahan, Wojciech Mostowski, Nadia Polikarpova, Christoph Scheben, Gerhard Schellhorn, Bogdan Tofan, Julian Tschannen, and Mattias Ulbrich. The COST IC0701 verification competition 2011. In Bernhard Beckert, Ferruccio Damiani, and Dilian Gurov, editors, Formal Verification of Object-Oriented Software, Revised Selected Papers Presented at the International Conference, FoVeOOS 2011, volume 7421 of Lecture Notes in Computer Science. Springer, 2012. [ bib | full text on HAL | .pdf ]
[5] Sylvain Conchon, Guillaume Melquiond, Cody Roux, and Mohamed Iguernelala. Built-in treatment of an axiomatic floating-point theory for SMT solvers. In Pascal Fontaine and Amit Goel, editors, SMT workshop, pages 12--21, Manchester, UK, 2012. LORIA. [ bib ]
[4] Claire Dross, Sylvain Conchon, Johannes Kanig, and Andrei Paskevich. Reasoning with triggers. In Pascal Fontaine and Amit Goel, editors, SMT workshop, Manchester, UK, 2012. LORIA. [ bib ]
[3] Denis Cousineau, Damien Doligez, Leslie Lamport, Stephan Merz, Daniel Ricketts, and Hernán Vanzetto. TLA+ proofs. In Dimitra Giannakopoulou and Dominique Méry, editors, 18th International Symposium on Formal Methods, volume 7436 of Lecture Notes in Computer Science, pages 147--154. Springer, 2012. [ bib | full text on HAL ]
[2] Denis Cousineau and Olivier Hermant. A semantic proof that reducibility candidates entail cut elimination. In Ashish Tiwari, editor, 23nd International Conference on Rewriting Techniques and Applications, volume 15 of Leibniz International Proceedings in Informatics (LIPIcs), pages 133--148, Nagoya, Japan, 2012. Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik. [ bib | DOI | full text on HAL ]
[1] Johannes Kanig, Edmond Schonberg, and Claire Dross. Hi-Lite: the convergence of compiler technology and program verification. In Ben Brosgol, Jeff Boleng, and S. Tucker Taft, editors, Proceedings of the 2012 ACM Conference on High Integrity Language Technology, HILT '12, pages 27--34, Boston, USA, 2012. ACM Press. [ bib ]