anchor.diff:      | FILTER | FIRST | FOLLOWING | FORMAT | FUNCTIONS
       | GRANT | GRANTS | GRAPHVIZ
       | HOUR
  -    | IF | INCLUDING | INPUT | INTEGER | INTERVAL | ISOLATION
  +    | IF | INCLUDING | INPUT | INTERVAL | ISOLATION
       | LAST | LATERAL | LEVEL | LIMIT | LOGICAL
       | MAP | MINUTE | MONTH
       | NFC | NFD | NFKC | NFKD | NO | NULLIF | NULLS
  
positive.code: INNER: 'INNER';
  INPUT: 'INPUT';
  INSERT: 'INSERT';
  INTEGER: 'INTEGER';
  INTERSECT: 'INTERSECT';
  INTERVAL: 'INTERVAL';
  INTO: 'INTO';
  
negative.code: SET: 'SET';
  SETS: 'SETS';
  SHOW: 'SHOW';
  SOME: 'SOME';
  START: 'START';
  STATS: 'STATS';
  