[graph1_on_transaction
     [any transaction (^$(no inheritance)$^),
          object: a thing,
          place: a region,
          seller: a person_or_organization (^$(explore 1)$^),
          customer: a person_or_organization (^$(explore 1)$^),
          asking_price: an asking_price,
          purchase_price: a purchase_price,
          may have for relation_from_situation_to_time (^$(explore)$^): a time_measure,
          may have for doer/object/result/place (^$(explore)$^): a thing,
          may have for relation_from_situation (^$(explore)$^): a thing]
];