Abstract. We describe the design and implementation of an automatic invariant generator for imperative programs. While automatic invariant generation through constraint solving has been extensively studied from a theoretical viewpoint as a classical means of program verification, in practice existing tools do not scale even to moderately sized programs. This is because the constraints that need to be solved even for small programs are already too difficult for the underlying (non-linear) constraint solving engines. To overcome this obstacle, we propose to strengthen static constraint generation with information obtained from static abstract interpretation and dynamic execution of the program. The strengthening comes in the form of additional linear constraints that trigger a series of simplifications in the solver, and make solving more scalable. We demonstrate the practical applicability of the approach by an experimental evaluation on a collection of challenging benchmark programs and comparisons with related tools based on abstract interpretation and software model checking. 1

I n recent years, advances in formal-proof systems and constraint solv-ers have enabled us to dream of a day when all the software we write can be proven correct. Software practi-tioners now must decide whether to persist in using testing to improve confidence in their code or to invest effort

Abstract. Given a set of processes and a set of tests on these processes we show how to define in a natural way three different eyuitalences on processes. ThesP equivalences are applied to a particular language CCS. We give associated complete proof systems and fully abstract models. These models

We present a new tool, named DART, for automatically testing software that combines three main techniques: (1) automated extraction of the interface of a program with its external environment using static source-code parsing; (2) automatic generation of a test driver for this interface

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We study the question of determining whether an unknown function has a particular property or is ffl-far from any function with that property. A property testing algorithm is given a sample of the value of the function on instances drawn according to some distribution, and possibly may query

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It is widely known that when there are errors with a moving-average root close to −1, a high order augmented autoregression is necessary for unit root tests to have good size, but that information criteria such as the AIC and the BIC tend to select a truncation lag (k) that is very small. We

We present a new symbolic execution tool, KLEE, capable of automatically generating tests that achieve high coverage on a diverse set of complex and environmentally-intensive programs. We used KLEE to thoroughly check all 89 stand-alone programs in the GNU COREUTILS utility suite, which form

The Edinburgh Logical Framework (LF) provides a means to define (or present) logics. It is based on a general treatment of syntax, rules, and proofs by means of a typed -calculus with dependent types. Syntax is treated in a style similar to, but more general than, Martin-Lof's system