LIT GUIDE keeps a step only when the smaller part is subtracted from the larger and both parts stay positive. 4/11 walks 4/11, 4/7, 4/3, 1/3, 1/2, 1/1. Five steps are kept and five subtractions the other way are dropped. The label of 4/11 is 36, and each of the first 200 labels is a different positive fraction that walks home. The denominators before the root sum to 26. A second run must match.
AMBER Calkin and Wilf are the assigned names for this enumeration of the positive rationals.
WALL The drawn path is 4/11. The uniqueness check stops at label 200, and the page does not draw every positive rational.
MODEL One pupil. Six posts step down from 4/11 to 1/1. A step is kept only when the subtraction stays positive. No cartridge is loaded.
Checking the herald.
Seal sha256(name|slug|blurb): 846e58ff1c906087f7b2f0df4ffa7dc0931ebe68e83e1764859935ecb56fd200