Joachim Jansen

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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 their 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)
Inductive definitions and justifications are well-studied concepts. Solvers that support inductive definitions have been developed, but several of their computationally nice properties have never been exploited to improve these solvers. In this paper, we present a new notion called relevance. We determine a class of literals that are relevant for a given(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)
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