RDF, CFL, ontology, language

In the frame of seeking an optimal formal language means for semantic web inferences a model and language RDF CFL has been developed. Using an intensional approach to the language semantics in its graph-based style of representation a demand of open world has been fulfilled. On the other side the RDF CFL system contains a package of inference methods working especially in closed-worlds, that have been developed in the clausal form of first order predicate logics, useful for solving a lot of tasks over corresponding knowledge bases. The article shows one of the capabilities of our RDF CFL graph language using as an example a well-known Castaněda’s puzzle that has been before used by some authors of new formal approaches, like for example Shapiro’s SNaPS for testing their possibilities. The believing versus knowing problem accompanying the puzzle brings into a discussion a further dimension. © Springer International Publishing AG, part of Springer Nature 2019.