anchor.diff:      ;
   
   subquery
  -    : matchNone
  +    : 'Default does not match anything'
       ;
   
   orderByClause
  
positive.code: 
  intervalExpr
      : INTERVAL expr ignoredIdentifier_
      ;
  
  privateExprOfDb
      : matchNone
      ;
  
  variable
  
negative.code: ignoredIdentifiers_
      : ignoredIdentifier_ (COMMA_ ignoredIdentifier_)*
      ;
  