A slot definition is a pair , where is a slot name and is a slot description. A slot description consists of an optional subslot-of component, itself a list of one or more slot names , followed by a list of zero or more global slot constraints (e.g., inverse) . We will write such a slot definition as:
Each global constraint on can be either:
We can now define how the function maps an OIL slot definition into a set of axioms. The definition is given in Figure 4, where and are slot names (or role names), is a class expression, is a global slot constraint and is a property.