Joachim Jansen

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FO(·) extends rst-order logic with inductive de nitions, partial functions, types and aggregates. Its model generator IDP3 rst grounds the theory and then uses search to nd the models. The grounder uses Lifted Unit Propagation (LUP) to reduce the size of the groundings of problem speci cations in IDP3. LUP is in general very e ective, but performs poorly on(More)
This paper provides a gentle introduction to problem solving with the IDP3 system. The core of IDP3 is a finite model generator that supports first order logic enriched with types, inductive definitions, aggregates and partial functions. It offers its users a modeling language that is a slight extension of predicate logic and allows them to solve a wide(More)
Dynamic systems play a central role in fields such as planning, verification, and databases. Fragmented throughout these fields, we find a multitude of languages to formally specify dynamic systems and a multitude of systems to reason on such specifications. Often, such systems are bound to one specific language and one specific inference task. It is(More)
Many state-of-the-art declarative systems use a ground-and-solve approach, where the problem statement, expressed in a high-level language, is first grounded into a low-level representation. Next, a solver is used to search a solution for the low-level representation. In order to prevent a combinatorial blowup of the grounding, many intelligent techniques(More)
Declarative systems aim at solving tasks by running inference engines on a specification, to free its users from having to specify how a task should be tackled. In order to provide such functionality, declarative systems themselves apply complex reasoning techniques, and, as a consequence, the development of such systems can be laborious work. In this(More)
Industrial Control Systems (ICS) are used for monitoring and controlling critical infrastructures such as power stations, waste water treatment facilities, traffic lights, and many more. Lately, these systems have become a popular target for cyber-attacks. Security is often an afterthought, leaving them vulnerable to all sorts of attacks. This article(More)
Opaque communications between groups of data processors leave individuals out of touch with the circulation and use of their personal information. Empowering individuals in this regard requires supplying them — or auditors on their behalf — with clear data handling guarantees. We introduce an inference model providing individuals with global(More)