Relation pm#from/to (situation,entity)
  supertype:  doer/object/result/place  where_relation
  subtype:  source (situation,causal_entity)
  subtype:  recipient (situation,entity)
     subtype:  beneficiary (situation,causal_entity)
  subtype:  from/to_place__from/toplace (process -> spatial_object)
     subtype:  from_place (process -> spatial_object)
     subtype:  to_place__destination (process -> spatial_object)
     subtype:  via_place__viaplace__via (process -> spatial_object)
     subtype:  path (process -> spatial_object)
  subtype:  origin__from (process,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:  destination__to (process,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'