Re:A Bad Trip to Infinity
by cjohnson318 on Saturday March 25, 2023 @04:13PM
(#35306786)
I always explain this with binary digits. You can always construct a new one from the diagonal by flipping each bit. I think the smaller domain {0,1} instead of {0,1,2,3,4,5,6,7,8,9} keeps people from getting distracted and trying to find a loophole.
[ Parent
| on HN ]
Binary is the only base where that proof does not work well easily, because 100000... = 011111...
in a metric system.
100000... is only equal to 011111... if your digits roll over, but if your digits roll over then you have a p-adic number system (specifically a 2-adic system), and the exact same argument would hold equally well for the 10-adic applied to 10000..... = 99999.....
You argument isn't dependent on being binary or not. Only that the numbers roll over.
Re:A Bad Trip to Infinity
by Dylan16807 on Saturday March 25, 2023 @07:30PM
(#35308714)
In bases higher than 2, you can avoid the issue entirely by saying that some digits get +1 and other digits get -1.
If the generated number only has digits 1-8, then 0000... vs 9999... is obviously not a problem.