Relation pm#before_situation (situation,situation)  in WebKB, do not use these relations, use their inverses
  supertype:  relation_from_situation_to_situation  after
  subtype:  previous_situation (situation -> situation)
  subtype:  beginning_situation__beginningsituation (situation -> situation)
  subtype:  precondition (process,situation)
  subtype:  cause (situation,situation)  see also rst#cause
     subtype:  causes (process,process)  the process in the 1st argument brings about the process in the 2nd argument