(define-concept P (or C0 C1 ... Cn) ) (disjoint Ci Cj) ( 0 ≤ i,j ≤ n, i ≠ j ).

Here (disjoint C_i C_j)a placeholder for the pair-wise disjointness of all C_i. Note that C_i can also be arbitrary concept expressions (even if this is not allowed in the original KRSS syntax).

In OWL 2 [2] the axioms can be expressed as follows (using OWL 2 Abstract Syntax):

EquivalentClasses(P, ObjectUnionOf(C1, ..., Cn))

DisjointClasses(C1, ..., Cn)

[1] Patel-Schneider, P. F., Swartout, B.: Description-Logic Knowledge Representation System Specification, 1993

[2] Motik, B., Patel-Schneider, P. F., Parsia, B.: OWL 2 Structural Specification and Functional-Style Syntax. W3C Candidate Recommendation 11 June 2009.

Aunt and ParentOfSon which are characterized by a relationships such as hasChild(resp. the inverse relationship hasParent), hasSibling, ' married-with as well as by the gender of people (Male respectively Female). There are a lot of similar ontologies about family relationships.

EquivalentClasses(Parent-Of-Son ObjectSomeValuesFrom (has-Child Male) ) EquivalentClasses(Parent-Of-Daughter ObjectSomeValuesFrom(has-Child Female) ) EquivalentClasses(Aunt ObjectIntersectionOf(Uncle-Or-Aunt Female)) EquivalentClasses(Uncle-Or-Aunt ObjectIntersectionOf(Person ObjectSomeValuesFrom(has-Sibling Parent)))

The concept Gender is partitioned in Male and Female. Applying this pattern results in the following axioms:

EquivalentClasses(Gender, ObjectUnionOf(Male Female)) DisjointClasses(Male Female)