I think this wording could be improved. I understood this rule to mean that the loop wouldn't have 1 follow 9, unless there was a 0. Therefore: 901 would be good, but 912 would not.

A second sentence like this one would help: "a sequence will not roll over after the last digit, so 1 will never follow 0"

This can be checked pretty easily:

> "".join(str(n) for n in range(1, 10000)).index('4949')
18685

Hi,

I tested 8 solutions in python/JS (most upvoted and users I trust about having a proper solution) and they all find 18685 for that input. Now,I'm not entirely sure which one of yours or the translator's solution found 18683 when I read your sentence. Could you clarify, plz?

that's right :) Thanks

....mark the issue as resolved, then?

It's highly unprobable. Please read this paragraph: https://docs.codewars.com/training/troubleshooting#kata-bug

There is no looping:

For incrementing sequences, 0 should come after 9, and not before 1, as in 7890.

For decrementing sequences, 0 should come after 1, and not before 9, as in 3210.