SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Function tupleElement (children 1)
     ExpressionList (children 2)
      Function reverse (children 1)
       ExpressionList (children 1)
        Identifier tuple
      Literal \'a\'
    Function tupleElement (children 1)
     ExpressionList (children 2)
      Function reverse (children 1)
       ExpressionList (children 1)
        Identifier tuple
      Literal \'b\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t_tuple
