## Sibling-Disjoint Exceptions

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| Sets and Individuals in CYC®
| Sibling-Disjoint Collections
| Covering Collections

If a type collection #$MyDisjointType whose instances are almost sibling-disjoint, the relation #$siblingDisjointExceptions gives us a way to still use #$MyDisjointType to state the disjoin, rather than creating a special instance of #$SiblingDisjointCollection with virtually the same set of instances.

Instead, we make #$MyDisjointType an instance of #$SiblingDisjointCollection and then for any two instances which are not disjoint, such as the collections B and D, we can assert:

         (#$siblingDisjointExceptions B D)

resulting in the following situation:

The constant R may not be an instance of both A and B because A and B are both instances of MyDisjointType. Q, however, may be an instance of both B and D, since (#$siblingDisjointExceptions B D) is true.

Last Update: 10/26/1998 11:41:18