anchor.diff:  RESERVE_DISK_SPACE:                    'RESERVE_DISK_SPACE';
   RESOURCE:                              'RESOURCE';
   RESOURCE_MANAGER_LOCATION:             'RESOURCE_MANAGER_LOCATION';
  -RESTRICTED_USER:                       'RESTRICTED_USER'; 
  +RESTRICTED_USER:                       'RESTRICTED_USER';
   RETENTION:                             'RETENTION';
   ROBUST:                                'ROBUST';
   ROOT:                                  'ROOT';
  
positive.code: fragment DEC_DIGIT:    [0-9];
  
  fragment FullWidthLetter
      : '\u00c0'..'\u00d6' 
      | '\u00d8'..'\u00f6' 
      | '\u00f8'..'\u00ff' 
      | '\u0100'..'\u1fff' 
      | '\u2c00'..'\u2fff' 
      | '\u3040'..'\u318f' 
      | '\u3300'..'\u337f' 
      | '\u3400'..'\u3fff' 
      | '\u4e00'..'\u9fff' 
      | '\ua000'..'\ud7ff' 
      | '\uf900'..'\ufaff' 
      | '\uff00'..'\ufff0'
      // | '\u10000'..'\u1F9FF'  //not support four bytes chars
      // | '\u20000'..'\u2FA1F'
  
negative.code: SHOWPLAN:                              'SHOWPLAN';
  SIGNATURE:                             'SIGNATURE';
  SIMPLE:                                'SIMPLE';
  SINGLE_USER:                           'SINGLE_USER';
  SIZE:                                  'SIZE';
  SMALLINT:                              'SMALLINT';
  SNAPSHOT:                              'SNAPSHOT';
  