RWTH Aachen University
In this paper, the authors study constraints for RDF-Schema (RDFS) graphs. The syntax and semantics is defined for constraints in graphs that can contain RDFS properties and blank nodes. The proposal for constraint satisfaction closely resembles the possible world approach found in various contexts of incomplete databases and knowledge bases. Positive decidability results for checking satisfaction of RDFS (Resource Description Framework Schema) constraints under blank nodes are given. In addition, they present deductive rules for different kinds of constraints and for several combinations of them.