Graphol is a visual language designed to help non-experts to understand and specify ontologies. Our language builds on the Entity-Relationship model, but has a formal semantics and higher expressiveness. Notably, OWL 2 can be completely encoded in Graphol. Thanks to the novel open-source Eddy ontology editor, designers can easily draw Graphol diagrams corresponding to OWL ontologies and export them into standard OWL 2 format. Both Graphol and Eddy have been used in several successful industrial projects and are currently under active development. This paper reports on our more recent progresses.

We define the class of e-bounded theories in the epistemic situation calculus, where the number of fluent atoms that the agent thinks may be true is bounded by a constant. Such theories can still have an infinite domain and an infinite set of states. We show that for them verification of an expressive class of first-order mu-calculus temporal epistemic properties is decidable. We also show that if the agent’s knowledge in the initial situation is e-bounded and the objective part of an action theory maintains boundedness, then the entire epistemic theory is e-bounded.