Incorporating Types of Types in Ontology-Driven Conceptual Modeling

The Unified Foundational Ontology (UFO) has been used to provide foundations for the major conceptual modeling constructs. So far, UFO has reflected a view in which domain entities are fundamentally divided into those that collect invariants of the domain (i.e., types) and those entities that manifest those invariants (i.e., instances), following the conventional two-level classification scheme. This paper extends UFO with support for multi-level classification schemes, in which some entities accumulate both type-like and instance-like characteristics. This requires an ontological interpretation and a formal theory of types of types. This theory is employed to engineer new constructs and constraints into the OntoUML language, and to develop computational support for the formal verification of constraint violation over multi-level conceptual models.