bal --flat
<<<
2008/01/01 January
    Expenses:Books          $10.00
    Assets:Cash

2008/01/01 January
    Expenses:One:Books          $10.00
    Expenses:One:Two:Books          $10.00
    Expenses:One:Two:Three:Books          $10.00
    Assets:Cash

2008/01/01 January
    Assets:Cash
    Income:Books          $-10.00

2008/01/01 January
    Assets:Cash
    Income:One:Books          $-10.00
    Income:One:Two:Books          $-10.00
    Income:One:Two:Three:Books          $-10.00
>>>1
              $10.00  Expenses:Books
              $10.00  Expenses:One:Books
              $10.00  Expenses:One:Two:Books
              $10.00  Expenses:One:Two:Three:Books
             $-10.00  Income:Books
             $-10.00  Income:One:Books
             $-10.00  Income:One:Two:Books
             $-10.00  Income:One:Two:Three:Books
>>>2
=== 0