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Several times in this discussion, it has been implied that using the right
langauge for floating point operations would prevent problems.  I would
like to point out that regardless of the language and particular floating
point format you choose such as HFP, BFP, or DFP, there will always be the
opportuntiy for errors to creep into floating point caculations due to the
fact that when two numbers are added, subtracted, multiplied, or divided
the result stored in a floating point format may round or truncate the
result to a finite value which is different from the actual result which
may be an irrational number in a given base such as 1/3 in base 2 or 10.

There are lots of examples of business caculations that require use of
floating point.  One example that comes to mind is the requirement for
many electric utilities to apply a fuel surcharge to monthly electrice
bills.  This rate is set by the Florida Public Service commission in
Florida and the staff works out details such as how irrational results
much be rounded to finite charge to be added to the bill. These
calculations are periodically audited to verify that they are done
according to the law.

Don Higgins
[email protected]

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