In order to design and implement tracers, one must decide what exactly to trace and how to produce this trace. On the one hand, trace designs are too often guided by implementation concerns and are not as useful as they should be. On the other hand, an interesting trace which cannot be produced efficiently, is not very useful either. In this article we propose a methodology which helps to effic...

In this paper, we study synthesis from logical specifications over finite traces expressed in LTLf and its extension LDLf . Specifically, in this form of synthesis, propositions are partitioned in controllable and uncontrollable ones, and the synthesis task consists of setting the controllable propositions over time so that, in spite of how the value of the uncontrollable ones changes, the spec...

FDBG (short for Finite domain DeBuGger) is a tool addressing the problems of debugging nite domain (FD) constraint programs. Implemented as a SICStus Prolog library, it allows CLP(FD) programmers to trace FD variable domain changes. FDBG is capable of detecting the wake-up of constraints as well as the steps of labeling, and it reports the e ects of these events on the variables. The simplest w...

While fixing concurrency bugs, program repair algorithms may introduce new concurrency bugs. We present an algorithm that avoids such regressions. The solution space is given by a set of program transformations we consider in for repair process. These include reordering of instructions within a thread and inserting atomic sections. The new algorithm learns a constraint on the space of candidate...

Deducibility constraints represent in a symbolic way the infinite set of possible executions of a finite protocol. Solving a deducibility constraint amounts to finding all possible ways of filling the gaps in a proof. For finite local inference systems, there is an algorithm that reduces any deducibility constraint to a finite set of solved forms. This allows one to decide any trace security pr...

We study the problem of enabling general 2D and 3D variational constraint representation to be used in conjunction with a feature hierarchy representation, where some of the features may use procedural or other non-constraint based representations. We trace the challenge to a requirement on constraint decomposition algorithms or decomposition-recombination (DR) planners used by most variational...

In this report, we show how to use the Simple Fluent Calculus (SFC) to specify generic tracers, i.e. tracers which produce a generic trace. A generic trace is a trace which can be produced by different implementations of a software component and used independently from the traced component. This approach is used to define a method for extending a java based CHR platform called CHROME (Constrain...

The generic trace format GenTra4CP has been defined in 2004 with the goal of becoming a standard trace format for the observation of constraint solvers over finite domains. It has not been used since. This paper defines the concept of generic trace formally, based on simple transformations of traces. It then analyzes, and occasionally corrects, shortcomings of the proposed initial format and sh...

CHR is a very versatile programming language that allows programmers to declaratively specify constraint solvers. An important part of the development of such solvers is in their testing and debugging phases. Current CHR implementations support those phases by offering tracing facilities with limited information.In this paper, we propose a new trace for CHR which contains enough information to ...

The symbolic verification of the security property of a cryptographic protocol for a bounded number of sessions is usually expressed as a symbolic trace reachability problem. Such a problem can be expressed as a constraint system for deducibility constraints for a certain inference system describing the possible actions of an attacker. We show that symbolic trace reachability for well-defined p...