anchor.diff:  
   == Fairwinds Game Tutorial F - Extinguishing Debt
   
  -Notice from the standings that Bob has a fc374 demand note written
  -against him as well as a negative fc70 net cash balance:
  +Notice from the standings that Bob has a fc374 demand note written against him
  +as well as a negative fc70 net cash balance:
   
   
   --------------------------------------------
  
positive.code:  91032ad7bbcb6c |         36 |    374 | bob    | bob
   fc074d501302eb |        413 |     70 | bob    | bob
  (4 rows)
  -------------------------------------------
  
  
  Bob's success at buying his own debt for zero cost results in completely 
  extinguishing his debt:
  
  -------------------------------------------
                                     Fairwinds Tournament Standings
   fairian_name | health_balance | wealth | cash_balance | bond_balance | note_balance | food_balance 
  --------------+----------------+--------+--------------+--------------+--------------+--------------
      ...       |                |        |              |              |              |
   bob          |       0.999995 |      0 |         0.00 |              |         0.00 |       50.189
      ...       |                |        |              |              |              |
  -------------------------------------------
  
  
  
  Lastly, while Bob has zero cash balance, he can call the notes he 
  owns to remove them if he wants:
  
  -------------------------------------------
  update note set called=true where debtor='bob';
  -------------------------------------------
  
  
  -------------------------------------------
                            Notes
   serial_number  | issue_date | amount | factor | debtor  
  ----------------+------------+--------+--------+---------
   f1f836cb4ea6ef |        411 |      5 |        | zachary
   0ade7c2cf97f75 |         33 |     45 |        | alice
  (2 rows)
  -------------------------------------------
  
  Take care to recall, however, as mentioned at the outset, this 
  strategy likely only works this well 
  if other 'Fairians' are not paying attention. In a competitive 
  market, others would be watching for profitable opportunities 
  and likely make bids competing with those shown above for 
  illustration, thus altering the outcome.
  
  
negative.code:     ...       |                |        |              |              |              |
  --------------------------------------------
   
  In a non-competitive market, Bob may have the opportunity to extinquish that
  debt by first issuing a bond in order to raise money, and then make a bid to
  buy the outstanding note. (The reason Bob needs to issue a bond is because
  having a negative net cash balance means that he will not be permitted to
  place any buy orders.)
  
  Bob raises cash by bootstrapping the bond market and borrowing:
  
  --------------------------------------------
  fairwinds=> insert into bond_ask default values;
  fairwinds=> insert into bond_ask default values;
  --------------------------------------------
  
  
  This leaves him in the same place in the standings overall, 
  but the details of his wealth are altered buy borrowing Faircoin:
  
  --------------------------------------------
                                     Fairwinds Tournament Standings
   fairian_name | health_balance | wealth | cash_balance | bond_balance | note_balance | food_balance 
  --------------+----------------+--------+--------------+--------------+--------------+--------------
      ...       |                |        |              |              |              |
   bob          |       0.999995 |   -444 |       930.00 |     -1000.00 |      -374.00 |       48.395
      ...       |                |        |              |              |              |
  --------------------------------------------
  
  That is, his net wealth remains unchanged at negative fc444, but he temporarily
  has cash on hand and so can place an order to buy the demand note upon which he
  is listed as the debtor:
  
  
  --------------------------------------------
  fairwinds=> insert into note_bid (serial_number) values ('91032ad7bbcb6c');
  INSERT 0 1
  --------------------------------------------
  
  
  which results in Bob becoming listed as factor as well as the debtor on bond
  `91032ad7bbcb6c`:
  
  --------------------------------------------
                            Notes
   serial_number  | issue_date | amount | factor | debtor  
  ----------------+------------+--------+--------+---------
   0ade7c2cf97f75 |         33 |     45 |        | alice
   f1f836cb4ea6ef |        411 |      5 |        | zachary
   91032ad7bbcb6c |         36 |    374 | bob    | bob
  --------------------------------------------
  
  
  
  Bob then waits for time to advance beyond the bond maturity. When the bond is
  redeemed, his fc70 cash short-fall results in a new bond, bond
  `fc074d501302eb`, scheduled for issuance ten clicks from the present at click
  413:
  
  --------------------------------------------
                            Notes
   serial_number  | issue_date | amount | factor | debtor  
  ----------------+------------+--------+--------+---------
  