On Tue, 07 Apr 2009 19:42:41 -0400, Bob Engelhardt
wrote:

Don Foreman wrote:
Some fairly heavy-duty math is behind software that does:
secure computing
encryption and decryption
compression
image processing
some controls, particularly controls that must not fail like
flight controls, refineries, etc.
...

I wouldn't disagree, but the key here is "... is behind software ...".
I.e., the math is the content, if you will, rather than the tool used to
develop the software. The math is in the coded algorithms, rather than
being an outside analytical tool.

I could be wrong, of course - it has been 17 years since I retired. If
so, I'd be very interested in seeing how software is modeled. Just
hearing what the parameters are would be interesting. Maybe I should
find a software NG to ask.

Bob

I understand the distinction. My understanding of how well-designed
software is designed and modelled is very sketchy but I worked with
people who did it very well indeed. The software was every bit as
robust as the hardware that executed it. Design was done before
coding ever started and typically accounted for 80% of the effort.
Well-designed robust software is not and can not be tinkered, hacked
or debugged into existance any more than good hardware is.

I'll forward your question to a friend and former colleague I highly
respect who knows a whole lot more than I do about this subject. He
might respond by email.