anchor.diff:  
    click | fairian_name |   debit   |  credit  | acknowledged |                        description                        
   -------+--------------+-----------+----------+--------------+-----------------------------------------------------------
  -    26 | bob          | 22.075329 |          | f            | total production from land 77de68daecd823
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 7b52009b64fd0a
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract bd307a3ec329e1
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract fa35e192121eab
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract f1abd670358e03
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 1574bddb75c78a
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 0716d9708d321f
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 9e6a55b6b4563e
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract b3f0c7f6bb763a
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 91032ad7bbcb6c
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 472b07b9fcf2c2
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 12c6fc06c99a46
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract d435a6cdd78630
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 4d134bc072212a
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract f6e1126cedebf2
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 887309d048beef
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract bc33ea4e26e5e1
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 0a57cb53ba59c4
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 7719a1c782a1ba
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 22d200f8670dbd
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract 632667547e7cd3
  -    26 | bob          |           | 1.003275 | f            | supplier production share paid on contract cb4e5208b4cd87
  +    26 | bob          | 21.071905 |          | f            | total production from land 77de68daecd823
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 7b52009b64fd0a
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract bd307a3ec329e1
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract fa35e192121eab
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract f1abd670358e03
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 1574bddb75c78a
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 0716d9708d321f
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 9e6a55b6b4563e
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract b3f0c7f6bb763a
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 91032ad7bbcb6c
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 472b07b9fcf2c2
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 12c6fc06c99a46
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract d435a6cdd78630
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 4d134bc072212a
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract f6e1126cedebf2
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 887309d048beef
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract bc33ea4e26e5e1
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 0a57cb53ba59c4
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 7719a1c782a1ba
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 22d200f8670dbd
  +    26 | bob          |           | 1.003268 | f            | supplier production share paid on contract 632667547e7cd3
       26 | bob          |           |        1 | f            | daily sustenance
       26 | bob          |           | 0.000163 | f            | spoilage
  +(23 rows)
  +--------------------------------------------
  +
  +
  +== Fairwinds Game Tutorial E - The Commodity Market
  +
  +The final market to illustrate is the commodity market, which  
  +is used to buy and sell food. To demonstrate this 
  +we have let the game time advance about 400 clicks so that the 
  +players cultivating land develop a food surplus. 
  +
  +
  +--------------------------------------------
  +     food_balance
  +
  + fairian_name |  balance  
  +--------------+-----------
  + alice        |  38.22213
  + bob          | 48.070724
  + cathy        | 19.109904
  + david        | 19.110119
  + edwin        | 24.034517
  + fredrick     | 24.034517
  + gina         | 24.034517
  + hendrik      | 24.034517
  + ingrid       | 24.034517
  + james        | 24.034517
  + karen        | 24.034517
  + leonard      | 24.034517
  + michelle     | 24.034517
  + norman       | 24.034517
  + olivia       | 24.034517
  + peter        | 24.034517
  + quincy       | 24.034517
  + robert       | 24.034517
  + samantha     | 24.034517
  + thomas       | 24.034517
  + ursula       | 24.034517
  + vincent      | 24.034517
  + wendy        | 24.034517
  + xavier       | 24.034517
   (24 rows)
  -
  ---------------------------------------------
  -
  -
  -== Fairwinds Game Tutorial E - The Commodity Market
  -
  -The final market to illustration is the commodity market. The 
  -commodity market is used to buy and sell food. To illustrate this 
  -we have let the game time advance about 400 clicks so that the 
  -players develop a food surplus. 
  -
  -'--- To Be Continued ---'
  -
  +--------------------------------------------
  +
  +James, Ingrid, and Gina place limit offers to sell a portion of 
  +their respective food surplus at various prices, resulting 
  +in different per-food-unit asking prices.
  +
  +
  +Gina:
  +
  +--------------------------------------------
  +insert into food_ask (expiration, quantity, price) values (40, 9, 5); 
  +--------------------------------------------
  +
  +Ingrid:
  +
  +--------------------------------------------
  +insert into food_ask (expiration, quantity, price) values (40, 10, 15);
  +--------------------------------------------
  +
  +James:
  +
  +--------------------------------------------
  +insert into food_ask (expiration, quantity, price) values (40, 11, 15);
  +--------------------------------------------
  +
  +
  +--------------------------------------------
  +fairwinds=> select * from food_ask;
  +
  + fairian_name | expiration | quantity | price |    unit_price     
  +--------------+------------+----------+-------+-------------------
  + james        |        441 |       11 |    15 | 1.36363636363636
  + ingrid       |        441 |       10 |    15 | 1.50
  + gina         |        441 |        9 |     5 | 0.555555555555556
  +(3 rows)
  +--------------------------------------------
  +
  +Then new player Zachary enters the game, issues a bond to raise
  +cash, and then places a market order to buy five food units:
  +
  +--------------------------------------------
  +fairwinds=> insert into food_bid (quantity) values (5);
  +--------------------------------------------
  +
  +
  +We can see the effect of these transactions in few different 
  +ways. First, re-listing the open commodity market sell orders 
  +after Zachary's purchase shows that the "best" (i.e, the lowest) 
  +unit price limit order was matched with Zachary's market order, 
  +since now only the sell orders for James and Ingrid remain:
  +
  +--------------------------------------------
  +fairwinds=> select * from food_ask;
  +
  + fairian_name | expiration | quantity | price |    unit_price    
  +--------------+------------+----------+-------+------------------
  + james        |        441 |       11 |    15 | 1.36363636363636
  + ingrid       |        441 |       10 |    15 |              1.5
  +(2 rows)
  +--------------------------------------------
  +
  +Next we can see the record of relvent cash transtions in the
  +cash_journal:
  +
  +--------------------------------------------
  +fairwinds=> select click, fairian_name, account, debit, credit, description 
  +			from cash_journal where click >= 400;
  +
  + click | fairian_name | account | debit | credit |        description         
  +-------+--------------+---------+-------+--------+----------------------------
  +   400 | zachary      | bond    |  1000 |        | Issued bond b6692ea5df920c
  +   401 | gina         | food    |     5 |        | Sold food quantity 7
  +   401 | zachary      | food    |       |      5 | Bought food quantity 7
  +(3 rows)
  +--------------------------------------------
  +
  +And we can see the effect of the food purchase in the food_journal:
  +
  +--------------------------------------------
  +fairwinds=> select * from food_journal where  fairian_name = 'zachary';
  +
  + click | fairian_name | debit | credit | acknowledged |  description  
  +-------+--------------+-------+--------+--------------+---------------
  +   401 | zachary      |     7 |        | f            | Bought food 5
  +(1 row)
  +--------------------------------------------
  +
  +
  +Note the food_journal shows Zachary buying 7 food units even though he
  +had bid for 5 units. This apparent discrepancy results from the fact
  +that the best match open sell order (that of Gina) was to sell 9 units, 
  +consequently the market order matching process struck a compromise 
  +quantity half-way between the quantity specifications on either side 
  +of the transaction and then executed
  +the transaction at the limit price Gina had specified. The net result is
  +that Gina sells at her specified Faircoin limit and at a per-unit 
  +price better than what she implicitely specified, i.e.,
  +
  +
  +$$ fc5 / 7 food units = 0.71428571428571428571 fc per unit $$
  +
  +
  +From Zachary the buyer's perspective, his cost matched the lowest 
  +offered selling price and he received more food than he bid for, 
  +and no other seller offered food at a lower unit cost that he 
  +ended up paying to Gina.
  +
  +
  
positive.code:  farmer     |         29 |   10 |             0 |     3 | bob          | 77de68daecd823 |  0.3
   farmer     |         29 |   10 |             0 |     2 | bob          | 77de68daecd823 |  0.2
   farmer     |         29 |   10 |             0 |     1 | bob          | 77de68daecd823 |  0.1
   farmer     |         29 |   10 |             0 |     0 | bob          | 77de68daecd823 |    0
  (21 rows)
  --------------------------------------------
  
  
negative.code:  vincent
   wendy
   xavier
  (24 rows)
  --------------------------------------------
  
  and wants to emulate and expand upon Alice's success with hiring.
  