Relation pm#example (?,pm#description_content/medium/container)
  exclusion:  rst#attributive_relation  pm#purpose  aktp#has-author  aktp#owned-by  pm#owner  pm#owner_of  sumo#leader  pm#seller  pm#customer  pm#generator  pm#creator  pm#spatial_origin  sumo#exploits  sumo#has_purpose  sumo#has_purpose_for_agent  pm#measure  pm#attribute  pm#name  dc#Date  rdf#value  pm#rdf_reification_relation  pm#support  pm#syntax  akts#has-magnitude
  subtype:  pm#illustration
  supertype:  pm#attributive_relation__attributiverelation (*)  like pm#binary_relation, this type mostly exists to categorize what cannot be categorized elsewhere
     supertype:  pm#relation_playing_a_special_role (*)  this type permits to categorize relations according to their roles ; this is a traditional but quite subjective way of categorizing relations
        >part of:  pm#relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type