OIL-Lite includes four kinds of axiom:

**disjoint**- a list of two or more class expressions that are pairwise disjoint, written .
**covered**- a single class expression that is covered by the succeeding list of class expressions, written .
**disjoint-covered**- a single class expression that is covered by the succeeding list of disjoint class expressions, written .
**equivalent**- a list of two or more class expressions that are equivalent, written .

Ian Horrocks 2000-09-10