anchor.diff:      ;
   
   onHistoryTableClause
  -    : LP_ HISTORY_TABLE EQ_ tableName (COMMA_ DATA_CONSISTENCY_CHECK EQ_ (ON | OFF))? RP_
  +    : LP_ HISTORY_TABLE EQ_ tableName (COMMA_ DATA_CONSISTENCY_CHECK EQ_ onOffOption_)? RP_
       ;
   
   tableExistClause_
  
positive.code:     ;
  
  dropConstraintOption
      : (MAXDOP EQ_ NUMBER_ | ONLINE EQ_ (ON | OFF) | MOVE TO (schemaName LP_ columnName RP_ | ignoredIdentifier_ | STRING_))
      ;
  
  dropColumnSpecification
  
negative.code:     ;
  
  dataConsistencyCheckClause_
      : COMMA_? DATA_CONSISTENCY_CHECK EQ_ onOffOption_
      ;
  
  historyRetentionPeriodClause_
  