(documentationdomainEnglishLanguage "Provides a computationally and heuristically convenient mechanism for declaring the argument types of a given relation. The formula (domain ?REL ?INT ?CLASS) means that the ?INT'th element of each tuple in the relation ?REL must be an instance of ?CLASS. Specifying argument types is very helpful in maintaining ontologies. Representation systems can use these specifications to classify terms and check integrity constraints. If the restriction on the argument type of a Relation is not captured by a Class already defined in the ontology, one can specify a Class compositionally with the functions UnionFn, IntersectionFn, etc.")