The Logic of Extensional RDFS

The normative version of RDF Schema (RDFS) gives nonstandard (intensional) interpretations to some standard notions such as classes and properties, thus departing from standard set-based semantics. In this paper we develop a standard set-based (extensional) semantics for the RDFS vocabulary while preserving the simplicity and computational complexity of deduction of the intensional version. This result can positively impact current implementations, as reasoning in RDFS can be implemented following common set-based intuitions and be compatible with OWL extensions.