On Sat, 17 Apr 2004 13:08:37 -0700, "Robert Swinney" wrote:
I think it is more efficient for many calculations, if you can keep track of
what's on the stack. It's also fun when some engineer borrows it at a
meeting and can't figure out how to multiply two numbers.

My point exactly. The engineer is unable to re-learn his math under
pressure (and he is math trained). So, the ordinary mortal is in for a ton
of confusion if he tries to figure out RPN. True, it makes lots of folks
break arms patting themselves on their backs over how smart they are - but -
the fact remains, RPN was introduced because of electronic limitations of
the time. Sphero explained it very well when he said that AE takes more
interim memory.

Well, when Jan Lukasiewicz invented polish notation in 1920, it wasn't to
save memory. When Charles Hamblin adapted it for calculation by changing
the operators from prefix to postfix, it was to save keystrokes, allow you to
start anywhere in an equation, see each intermediate result, and have a
reasonable confidence that you'd wind up with the correct final result.

As John noted, RPN works exactly the way you'd do the calculations with
pencil and paper, so it is a natural and familiar way to work for people who
are comfortable with doing hand calculation.

Gary