SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function equals (children 1)
     ExpressionList (children 2)
      Function concat (children 1)
       ExpressionList (children 3)
        Literal \'a\'
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal \'b\'
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal \'c\'
      Literal \'abc\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.numbers
   Literal UInt64_5