SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function less (children 1)
     ExpressionList (children 2)
      Literal \'a\\0\\0\\0\\0\'
      Literal \'a\\0\\0\\0\'
    Function greater (children 1)
     ExpressionList (children 2)
      Literal \'a\\0\\0\\0\\0\'
      Literal \'a\\0\\0\\0\'
