Relation pm#relation_from_situation_to_situation (pm#situation,pm#situation)
  exclusion:  pm#relation_from_situation_to_time  pm#relation_from_time_to_situation  pm#relation_to_time  pm#temporal_relation
  supertype:  pm#relation_from_situation  pm#relation_to_situation  pm#when_relation
  subtype:  pm#later_situation__latersituation (pm#situation,pm#situation)
     subtype:  pm#next_situation (pm#situation -> pm#situation)
        subtype:  pm#successor (pm#situation -> pm#situation)
     subtype:  pm#ending_situation__termination (pm#situation -> pm#situation)
     subtype:  pm#postcondition (pm#process,pm#situation)
     subtype:  pm#consequence (pm#situation,pm#situation)  see also rst#effect
  subtype:  pm#before_situation (pm#situation,pm#situation)  in WebKB, do not use these relations, use their inverses
     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