Walkthrough style

Taken from OpenAI, How the Ideas Came Together (reasoning-walkthroughs.pdf).

A WALKTHROUGH.md is a discovery narrative, not a paper. Required beats:

0. What was actually missing (the degree of freedom, not a restatement)
1. Named false starts, with the specific obstruction
2. The useful failure (what the dead end taught)
3. The click
4. The argument, in the order it was found
5. Computer search (a matrix, a SAT log, a table)
6. What is proved vs still open

Do not clean the path. Do not invent a write-up that pretends a search succeeded. Empty sections mean the quest is not done.