Abstract. We, the organizers and participants, report our experiences from the 1st Verified Software Competition, held in August 2010 in Edinburgh at the VSTTE 2010 conference.

Abstract. In this work we present a translation validation approach to encode a sound execution semantics for the ATL specification. Based on our sound encoding, the goal is to soundly verify an ATL specification against the specified OCL contracts. To demonstrate our approach, we have developed the VeriATL verification system using the Boogie2 intermediate verification language, which in turn provides access to the Z3 theorem prover. Our system automatically encodes the execution semantics of each ATL specification (as it appears in the ATL matched rules) into the intermediate verification language. Then, to ensure the soundness of the encoding, we verify that it soundly represents the runtime behaviour of its corresponding compiled implementation in terms of bytecode instructions for the ATL virtual machine. The experiments demonstrate the feasibility of our approach. They also illustrate how to automatically verify an ATL specification against specified OCL contracts.

Abstract. This paper reports on the experiences with the program verification competition held during the FoVeOOS conference in October 2011. There were 6 teams participating in this competition. We discuss the three different challenges that were posed and the solutions developed by the teams. We conclude with a discussion about the value of such competitions and lessons that can be learned from them.

Abstract-In this paper we present an approach to generating instances of metamodels using a Satisfiability Modulo Theories (SMT) solver as a back-end engine. Our goal is to automatically translate a metamodel and its invariants into SMT formulas which can be investigated for satisfiability by an external SMT solver, with each satisfying assignment for SMT formulas interpreted as an instance of the original metamodel. Our automated translation works by interpreting a metamodel as a bounded Attributed Type Graph with Inheritance (ATGI) and then deriving a finite universe of all bounded attribute graphs typed over this bounded ATGI. The graph acts as an intermediate representation which we then translate into SMT formulas. The full translation process, from metamodels to SMT formulas, and then from SMT instances back to metamodel instances, has been successfully automated in our tool, with the results showing the feasibility of this approach.

This paper presents a technique for translating common comprehension expressions ( sum , count , product , min , and max ) into verification conditions that can be tackled by two off-the-shelf first-order SMT solvers. Since a firstorder SMT solver does not directly support the bound variables that occur in comprehension expressions, the challenge is to provide a sound axiomatisation that is strong enough to prove interesting programs and, furthermore, that can be used automatically by the SMT solver. The technique has been implemented in the Spec# program verifier. The paper also reports on the experience of using Spec# to verify several challenging programming examples drawn from a textbook by Dijkstra and Feijen.

This paper presents a formalisation of the Event-B formal specification language in terms of the theory of institutions. The main objective of this paper is to provide: (1) a mathematically sound semantics and (2) modularisation constructs for Event-B using the specification-building operations of the theory of institutions. Many formalisms have been improved in this way and our aim is thus to define an appropriate institution for Event-B, which we call EVT. We provide a definition of EVT and the proof of its satisfaction condition. A motivating example of a traffic-light simulation is presented to illustrate our approach.

The refinement-based approach to developing software is based on the correct-by-construction paradigm where software systems are constructed via the step-by-step refinement of an initial highlevel specification into a final concrete specification. Proof obligations, generated during this process are discharged to ensure the consistency between refinement levels and hence the system's overall correctness.Here, we are concerned with the refinement of specifications using the EVENT B modelling language and its associated toolset, the RODIN platform. In particular, we focus on the final steps of the process where the final concrete specification is transformed into an executable algorithm. The transformations involved are (a) the transformation from an EVENT B specification into a concrete recursive algorithm and (b) the transformation from the recursive algorithm into its equivalent iterative version. We prove both transformations correct and verify the correctness of the final code in a static program verification environment for C# programs, namely the Spec# programming system.

Abstract. VerifyThis 2012 was a two-day verification competition taking place as part of the International Symposium on Formal Methods (FM 2012) on August 30-31, 2012 in Paris, France. It was the second installment in the VerifyThis series. After the competition, an open call solicited contributions related to the VerifyThis 2012 challenges and overall goals. As a result, seven papers were submitted and, after review and revision, included in this special issue.In this introduction to the special issue, we provide an overview of the VerifyThis competition series, an account of related activities in the area, and an overview of solutions submitted to the organizers both during and after the 2012 competition. We conclude with a summary of results and some remarks concerning future installments of VerifyThis.