[pm#graph1_on_file
     [any #file,
          may have for pm#url: a pm#URL,
          pm#result of: a #writing,
          pm#authoring_date: a pm#time_measure,
          may have for pm#creator: a #person,
          may have for dc#Creator: a pm#string,
          may have for #size: a #computer_memory_unit,
          may have for pm#format: a #data_format,
          may have for pm#title: a pm#string,
          may have for dc#Coverage: a pm#thing,
          pm#descr of: a pm#situation]
];