Normalisations of Existential Rules: Not so Innocuous!
From International Center for Computational Logic
Normalisations of Existential Rules: Not so Innocuous!
Talk by David Carral
- Location: APB room 3027
- Start: 17. November 2022 at 11:00 am
- End: 17. November 2022 at 12:00 pm
- Event series: Research Seminar Logic and AI
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Existential rules are an expressive knowledge representation language mainly developed to query data. In the literature, they are often supposed to be in some normal form that simplifies technical developments. For instance, a common assumption is that rule heads are atomic, i.e., restricted to a single atom. Such assumptions are considered to be made without loss of generality as long as all sets of rules can be normalised while preserving entailment. However, an important question is whether the properties that ensure the decidability of reasoning are preserved as well. We provide a systematic study of the impact of these procedures on the different chase variants with respect to chase (non-)termination and FO-rewritability. This also leads us to study open problems related to chase termination of independent interest.
