Fixed-Domain Reasoning for Description Logics

Talk by Lukas Schweizer

Location: APB 3027
Start: 20. April 2016 at 2:50 pm
End: 20. April 2016 at 3:30 pm
Research group: Computational Logic
Event series: KBS Seminar
iCal

Description logics (DLs) are currently a de facto standard in logic-based knowledge representation thanks to the last two decades of research and their use as the underpinning of standardized and widely adopted web ontology language (OWL), which also comes with the ad- vantage of existing user-friendly modeling tools. It has, however, been observed that OWL and description logics (DLs) are utilized by logically less skilled practitioners as constraint languages adopting a closed-world assumption, contrary to the open world semantics imposed by the clas- sical definitions and the standards. Therefore, we came up with an al- ternative formal semantics reflecting this “off-label use” of these widely adopted formalisms. To that end, we introduce the fixed domain seman- tics and discuss that this semantics gives rise to the interesting new inferencing task of model enumeration. We describe how the new seman- tics can be axiomatized in very expressive DLs. We thoroughly investi- gate the complexities for standard reasoning as well as query answering for a wide range of DLs. We present an implementation of a fixed do- main DL reasoner based on the translation into answer set programming (ASP) and provide first results that this tool is superior to alternative approaches when used on constraint-satisfaction-type problems.