[pm#graph1_on_spatial_object
     [any pm#spatial_object (^$(no inheritance)$^),
          menu#spatial_characteristic (^$(explore 1)$^): a pm#spatial_attribute_or_quality_or_measure,
          pm#relation_to_another_spatial_object (^$(explore 2)$^): a pm#spatial_object,
          may have for pm#owner: a menu#person_or_organization (^$(explore 1)$^),
          #monetary_value: a #monetary_value,
          may be pm#object of: a pm#commercial_transaction (^$(explore 1)$^),
          pm#place of: a pm#situation]
];