In reply to:

>(3.00000...0001) [that is, an infinite number of zeros before the final one])

you lose me with this. how can you have a *final one after an *infinite number of zeros??

Well it seems as easy to visualize (4 minus 0.99999...) as it does to visualize (2.99999999...). They are each numbers that are very close to three, but on opposite sides of the integer three. I was expressing (4-0.99999...) as 3.000...0001. Maybe it would have been more precise to have expressed it as simply (4-0.99999...).