Short-circuit Logic

[Roy Smith]

In article <qotk3mhx78l.fsf at ruuvi.it.helsinki.fi>,
 Jussi Piitulainen <jpiitula at ling.helsinki.fi> wrote:

> I wonder why floating-point errors are not routinely discussed in
> terms of ulps (units in last position).

Analysis of error is a complicated topic (and is much older than digital 
computers).  These sorts of things come up in the real world, too.  For 
example, let's say I have two stakes driven into the ground 1000 feet 
apart.  One of them is near me and is my measurement datum.

I want to drive a third stake which is 1001 feet away from the datum.  
Do I measure 1 foot from the second stake, or do I take out my 
super-long tape measure and measure 1001 feet from the datum?