Isabelle/DOF: Design and Implementation

DOF is a novel framework for defining ontologies and enforcing them during document development and document evolution. A major goal of DOF is the integrated development of formal certification documents (e.g., for Common Criteria or CENELEC 50128) that require consistency across both formal and informal arguments. To support a consistent development of formal and informal parts of a document, we provide Isabelle/DOF, an implementation of DOF on top of Isabelle/HOL. Isabelle/DOF is integrated into Isabelle's IDE, which allows for smooth ontology development as well as immediate ontological feedback during the editing of a document. In this paper, we give an in-depth presentation of the design concepts of DOF's Ontology Definition Language (ODL) and key aspects of the technology of its implementation. Isabelle/DOF is the first ontology language supporting machine-checked links between the formal and informal parts in an LCF-style interactive theorem proving environment. Sufficiently annotated, large documents can easily be developed collaboratively, while ensuring their consistency, and the impact of changes (in the formal and the semi-formal content) is tracked automatically.