Nested contextualised views in the web of data

The notion of context is important since it can capture many of the interesting aspects of the way we understand the world such as relativity, locality, partiality, and context-dependence. In this work, we define the contextual RDFS model theory, called c-RDFS model theory for short, where a context is a triple of a name, a c-RDF graph, and a set of references (links) from resources to other contexts. This way chains of nested contextualised views are formed, where corresponding contexts can be complementary or conflicting. A collection of such chains forms a contextual structure. The c-RDFS model theory is developed extending the RDFS 1.1 model theory, which supports inferences both within contexts but also across contexts. Entailment of contextual structures is defined extending RDFS entailment between RDF graphs. For querying contextual structures, an extension of the SPARQL 1.0 language is proposed which allows querying one context at a time (thus delimiting a portion of interest) but also navigation through the references of a context reaching the contextual views of the desired resources.