anchor.diff:  fragment W : [wW];
   fragment X : [xX];
   fragment Y : [yY];
  -fragment Z : [zZ];+fragment Z : [zZ];
  
positive.code: NOT : N O T;
  OR: O R;
  REGEXP_LIKE: R E G E X P '_' L I K E;
  LIKE: L I K E;
  ORDER: O R D E R;
  SELECT: S E L E C T;
  TOP: T O P;
  
negative.code: 
  regexpLikeClause:
    REGEXP_LIKE '(' expression ',' literal ')';
  
  booleanOperator: OR | AND;
  
  groupByClause: GROUP BY groupByList;
  