Domain ontology

wikipedia says: A domain subclass of::ontology (or domain-specific ontology) models a specific domain, or part of the world. It represents the particular meanings of terms as they apply to that domain.

mathematical domain ontology
The EngMath ontology is an ontology for mathematical modeling in engineering. It has been specified by Gruber & Olsen in An Ontology for Engineering Mathematics and is available in the Ontolingua ontology library.