LIT LOCKSMITH keeps a step only when it is the larger digit order minus the smaller. 1234 goes 3087, 8352, 6174. Three steps are kept and three reversed offers are dropped. Every one of the 8991 four-digit numbers with two different digits reaches 6174, and none takes more than 7 steps. The law sums to 7. A second run must match.
AMBER D. R. Kaprekar described this routine and the fixed point 6174. The biography is assigned.
WALL The census stops at four digits. It does not follow numbers with more digits, and it is not a claim about a person beyond the routine.
MODEL One pupil. The stage is the lock the pupil reached. A rearrangement is kept only when the gap is the true subtraction. No cartridge is loaded.
Checking the teller.
Seal sha256(name|slug|blurb): 8cae74178e960cdff0ef82c24c318f45874f3bb5a452adf7fef6c2fc71b60385