[pm#graph1_on_housing
     [any #housing (^$(no inheritance)$^),
          #address: an #address,
          may have for pm#phone_No: a pm#string,
          may have for pm#fax_No: a pm#string,
          may have for pm#owner: a menu#person_or_organization (^$(explore 1)$^),
          may have for pm#facility: a #facility (^$(explore 2)$^),
          may have for pm#part: a #room,
          may be pm#object of: a pm#commercial_transaction (^$(explore 1)$^),
          #monetary_value: a #monetary_value,
          may be pm#doer/object/result/place of (^$(explore)$^): a pm#situation]
];