Let the user deposit time, lend files & bytes from
the bank, lend creds to another user, gamble for 
time.
The SysOp can take interest on lent creds, and give
interest to deposited time. 
For Cnet 2.63+

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]                23712   43524  54.5% -lh5- 7b5b Apr 13  1995 ConfigCredX
[generic]                 8801   13820  63.7% -lh5- 4fb5 Apr 18  1995 CredMaint
[generic]                13680   23472  58.3% -lh5- ab0b Apr 18  1995 CredX
[generic]                 1308    3059  42.8% -lh5- 0ffd Apr 18  1995 CredX.doc
[generic]                  256     495  51.7% -lh5- c8bd Apr 18  1995 file_id.diz
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         5 files   47757   84370  56.6%            Apr 25  1995