Why we pivoted then
Every item in F6's table is now closed or blocked, which is the rule for leaving a family. The next family in the ranking was F3, but Alexis asked to start over at F1 and unblock what was blocked before the sweep goes on (issue #50). Most of the blocked cells were blocked for the same reason: the 24 known letters leave them consistent, as they leave most scrambled copies consistent, so only an English test could judge them, and 0120 showed the English climb we had cannot recover a planted message at that size. That reason is a property of our climb, not of the cells, so it can be worked on. The ranking is unchanged.
What happened before
- 0119-0124 settled one and two unknown alphabets with no move exactly, except the lengths where they fit as the copies do (F1.1, F1.2, blocked).
- 0129-0133 carried the same exact tests through every move and left the same kind of residue (F6.1, F6.2, blocked).
- 0134-0135 closed the three-stage readings and the hand padding. The three-stage row was marked closed, but its mixed triples at widths 25-96 rest on 0037's 200,000-triple sample.
The change we believe is needed
- F1.5, the shared blocker. First an exact bound: for each blocked cell, the key's bits against the redundancy of the 73 unknown letters. A cell above the bound cannot be judged by any English test and is blocked for good, with a number instead of a reason. Then, for cells under the bound, a climb that keeps the known letters consistent at every step (0120's climb moved the forced key values in every slot with one swap), measured on planted texts by 0120's own power bar before it touches K4. If a design passes, the cells it covers reopen in F1, F6 and F8 and are worked in rank order. After two designs fail, F1.5 is blocked with both recorded (stop rule proposed by Claude; adopted 2026-10-16, Alexis delegated the decision).
- F6.3b. Enumerate the mixed triples at widths 25-96 exactly, as 0134 did at 2-24.
- F9.1. Write the bounded list of hand transpositions that F9's last row lacked, then test it as 0106 did.
- Unchanged: K5 as a key (no text) and a code layer or another language (needs a codebook, or contradicts the English known letters) stay blocked.
After F1 and F6 the loop goes on through F3, F2, F4, F8, F5 and F9 as ranked.