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