Propositional Encoding of Constraints over Tree-Shaped Data

We present a functional programming language for specifying constraints over tree-shaped data. The language allows for Haskell-like algebraic data types and pattern matching. Our constraint compiler CO4 translates these programs into satisfiability problems in propositional logic. We present an application from the area of automated analysis of (non-)termination of rewrite systems

BigraphER: rewriting and analysis engine for bigraphs

BigraphER is a suite of open-source tools providing an effi- cient implementation of rewriting, simulation, and visualisation for bigraphs, a universal formalism for modelling interacting systems that evolve in time and space and first introduced by Milner. BigraphER consists of an OCaml library that provides programming interfaces for the manipulation of bigraphs, their constituents and reaction rules, and a command-line tool capable of simulating Bigraphical Reactive Systems (BRSs) and computing their transition systems. Other features are native support for both bigraphs and bigraphs with sharing, stochastic reaction rules, rule priorities, instantiation maps, parameterised controls, predicate checking, graphical output and integration with the probabilistic model checker PRISM

Weight-Aware Core Extraction in SAT-Based MaxSAT Solving

Peer reviewe

Solving and Verifying the Boolean Pythagorean Triples Problem via Cube-and-Conquer

We solved a long-outstanding open problem in Ramsey theory, using SAT solving

SPASS-SATT: A CDCL(LA) Solver

International audienceSPASS-SATT is a CDCL(LA) solver for linear rational and linear mixed/integer arithmetic. This system description explains its specific features: fast cube tests for integer solvability, bounding transformations for unbounded problems, close interaction between the SAT solver and the theory solver, efficient data structures, and small-clause-normal-form generation. SPASS-SATT is currently one of the strongest systems on the respective SMT-LIB benchmarks

A Proof-Theoretic Perspective on SMT-Solving for Intuitionistic Propositional Logic

Claessen and R\uf3sen have recently presented an automated theorem prover, intuit, for intuitionistic propositional logic which utilises a SAT-solver. We present a sequent calculus perspective of the theory underpinning intuit by showing that it implements a generalisation of the implication-left rule from the sequent calculus LJT, also known as G4ip and popularised by Roy Dyckhoff

Automatic Quality-of-Service Evaluation in Service-Oriented Computing

Part 5: Tools (2)International audienceFormally describing and analysing quantitative requirements of software components might be important in software engineering; in the paradigm of API-based software systems might be vital. Quantitative requirements can be thought as characterising the Quality of Service – QoS provided by a service thus, useful as a way of classifying and ranking them according to specific needs. An efficient and automatic analysis of this type of requirements could provide the means for enabling dynamic establishing of Service Level Agreements – SLA, allowing for the automatisation of the Service Broker.In this paper we propose the use of a language for describing QoS contracts based on convex specification, and a two-phase analysis procedure for evaluating contract satisfaction based on the state of the art techniques used for hybrid system verification. The first phase of the procedure responds to the observation that when services are registered in repositories, their contracts are stored for subsequent use in negotiating SLAs. In such a context, a process phase of contract minimisation might lead to great efficiency gain when the second, and recurrent, phase of determining QoS compliance is run