Place Names Ontologies - Advances in Cartography and GIScience - page 340

5.1.4 Symmetrical relationship
Symmetrical relationship is defined if for a relationship, the object and the
subject may be exchanged without changing of the meaning (see Figure 5 ) .
Example: County (Istarska županija) is connected to Town (Pula), and
Town (Pula) is connected to County (Istarska županija), if this is the truth,
relationship is symmetrical.
Figure 5: An example of the Symmetrical relationship.
5.1.5 Antisymmetric relationship
Antisymmetric relationship is defined if object A has a relationship to
object B, than object B can never have this relationships to object A
(see Figure 6 ).
Example: Sea channel (Hvarski kanal) is part of Sea (Jadransko more) and
Sea (Jadransko more) is not part of Sea channel (Hvarski kanal), then
relationship is antisymmetric.