Relation pm#what_relation (*)
  subtype:  object/result  process_attribute  mereological_relation  method  relation_from_collection  relation_to_collection  contextualizing_relation
  supertype:  wh-/how_relation (*)  this type permits to categorize relations according to the usual who/what/why/where/when/how questions ; this is a traditional but very subjective and ineffective way of categorizing relations 
     >part of:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type