@LiseAndreasen@mastodon.world let a and b be the two random numbers on the Cantor set and assume without loss of generality that a <= b. Divide into cases according to which ternary digit is the first to differ. In 1/2^n cases, that digit is the nth (there is a 1/2 chance that the first pair is the same, 1/2 that the second is, and so on, and finally we have a 1/2 chance that the nth pair differs). In that case, the difference truncated at the nth digit is 2/3^n,