[pm#graph1_on_ontology
     [any pm#ontology (^$(no inheritance)$^),
          may have for pm#member: several pm#category_identifier,
          may have for pm#member: several pm#category_definition,
          pm#result of: a #creation,
          may have for pm#creator: a #person,
          may have for pm#url: a pm#URL]
];