Relation akts#hour-of (time_point,nonnegative_integer)
  supertype:  temporal_relation_from_time_point (time_point,nonnegative_integer)
     supertype:  temporal_relation (?,?)
        supertype:  temporal_relation (?,?)
           supertype:  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:  relation__related_thing__relatedthing___related_with  type for any relation (unary, binary, ..., *-ary) and instance of pm#relation_type
           supertype:  when_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