Relation pm#from/to (pm#situation,pm#entity)
  supertype:  pm#doer/object/result/place  pm#where_relation
  subtype:  pm#source (pm#situation,pm#causal_entity)
  subtype:  pm#recipient (pm#situation,pm#entity)
     subtype:  pm#beneficiary (pm#situation,pm#causal_entity)
  subtype:  pm#from/to_place__from/toplace (pm#process -> pm#spatial_object)
     subtype:  pm#from_place (pm#process -> pm#spatial_object)
     subtype:  pm#to_place__destination (pm#process -> pm#spatial_object)
     subtype:  pm#via_place__viaplace__via (pm#process -> pm#spatial_object)
     subtype:  pm#path (pm#process -> pm#spatial_object)
  subtype:  sumo#origin__from (sumo#process,sumo#object)  the 2nd argument (which must be present at least at the beginning of the process) indicates where the process began; for example, the submarine is the origin in 'the missile was launched from a submarine'
  subtype:  sumo#destination__to (sumo#process,pm#entity)  the 2nd parameter is the target or goal of the process; for example, Danbury would be the destination in 'Bob went to Danbury'; this is a very general case_role which, in particular, that it covers the concepts of 'recipient' and 'beneficiary'; thus, John would be the destination in 'Tom gave a book to John'