Relation EXHAUSTIVE-SUBCLASS-PARTITION

A subrelation-partition of a class C is a set of mutually-disjoint classes (a subclass partition) which covers C. Every instance of C is is an instance of exactly one of the subclasses in the partition.
Arity: 2
Subrelation-Of: Subclass-partition
Axioms:
(<=> (Exhaustive-Subclass-Partition ?C ?Class-Partition)
     (And (Subclass-Partition ?C ?Class-Partition)
          (Forall (?Instance)
                  (=> (Instance-Of ?Instance ?C)
                      (Exists (?Subclass)
                              (And (Member ?Subclass
                                           ?Class-Partition)
                                   (Member ?Instance ?Subclass)))))))