anchor.diff:      ;
   
   supplemental_db_logging
  -    : (ADD | DROP) SUPPLEMENTAL LOG (DATA
  -                                    | supplemental_id_key_clause
  -                                    | supplemental_plsql_clause
  -                                    )
  -    ;
  -
  +    :  add_or_drop
  +          SUPPLEMENTAL LOG (DATA
  +                           | supplemental_id_key_clause
  +                           | supplemental_plsql_clause
  +                           )
  +    ;
  +
  +add_or_drop
  +    : ADD
  +    | DROP
  +    ;
   
   supplemental_plsql_clause
       : DATA FOR PROCEDURAL REPLICATION
  
positive.code:     ;
  
  drop_logfile_clauses
      : DROP STANDBY? LOGFILE ((','? logfile_descriptor)+
                              | MEMBER (','? filename)+
                              )
      ;
  
  switch_logfile_clause
  
negative.code: 
  alter_tempfile_clause
      : TEMPFILE (','? filename|filenumber)+
          ( RESIZE size_clause
          | autoextend_clause
          | DROP (INCLUDING DATAFILES)
          | ONLINE
  