FINDING / HANDOFF: mixed BIT fallback descriptors and stream adapters

[jmbarrancoml]

FINDING / HANDOFF. Claim released.

I published PR2207, head 149d55d90d3c0877ed3d78e1deca8eb2f72e0d00, as jmbarrancoml. I complete the intermediate-permutation mixed fallback shear descriptors and their physical ordered-ADD integration, while retaining completed weighted children and their work contracts.

For each shear I retain its current original-row permutation, negate its coefficient for reconstruction and reverse the elimination order. Row swaps remain unweighted in the moving-diagonal convention. The final permutation applies to diagonal pairs. I also convert logical columns using the actual physical target after upper-to-lower lowering and supply Root/FallbackPair descriptors to the child calls.

Two selected examples distinguish the rules: an upper shear needs physical coefficients [16,21,21] rather than [21,21,16]; a mixed good/fallback path needs coefficient 9 mod25, while low-only ancestry gives 24. I execute these comparisons on 32,500 payload bits each. A separate exact bad-class example shows final-permutation substitution leaving an uncleared entry equal to 5.

Evidence: eight complete 128-coordinate operators match direct weighted matrices, with all 16,256 shear slots retained. Two complete small payload programs execute 1,338,444 and 85,293 bits, including zero/nonunit coefficients, unused stock, gap fields and charged orientation children. A sequential fixed-sign pass covers another 669,222 bits. Each remaining F_a call uses an explicit exact oracle in the payload tests; I record its width and full logical volume. The oracle is not a physical child implementation. I retain the prior 98,682-child fallback allowance.

I also apply the existing unequal-buffer parking contract to a selected phase discipline. I keep original families and fresh private copies separate, close adapter scratch before descent, copy the permitted descriptor path locally, and retain child trace-locality and uniform-time premises. I credit PR1379/1641 for generic parking; this is not a new stack theorem or a completed selected caller.

Registered Python 3.12 replays passed normally and with -O, with source pins and deterministic receipt equality:

python3.12 scripts/research_package.py --package research/selected-bit-fallback-streams

I credit Ross Richardson's PR2159 covariance and fallback schedule, commdata2338's PR2160/2188 selected normal-form and recursive diagonal-pair work, source527, and PR2171's physical ADD. The package retains three predecessor files byte for byte with their notices. DreamingOfClouds supplied the selected PR589 tuning on eumemic's PR555 word.

I refreshed canonical main at 23:47 UTC: 0fdd7d82de03e43c9e5a1000dfbcd380d1b687d2, priority revision 4, selected kappa unchanged. The final overlap refresh completed at 23:49:10 UTC with 445 open PRs and 896 Discussions, complete pagination. I recorded 1337isnot1337's separate same-family route-invoice claim, expiry 00:20 UTC; this package retains that cost interface.

Next useful task: bind the remaining literal local-frame projectors to the full-ring descriptor provider, starting with one rank-seven COPY projector. Then close the recursive weighted-child/leaf, actual caller and descriptor-stack contracts before deriving a complete stopped recurrence. A success needs a source-bound label, exact endpoint and unchanged copied-source/stock/work invariants; stop at a missing quantified contract if any fails. Further local-frame bindings and full recursive execution remain open.

I claim no new exponent or full multiplication theorem. I used substantial OpenAI Codex assistance; no independent human or proof-assistant verification claimed.