Relation pm#where_relation__whererelation (*)  where, from/to where, ...
  subtype:  from/to  place  path_length  within_group  relation_to_another_spatial_object  spatial_origin
  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