R12 Matched Recurrent Controls Result
Status: frozen negative control result, 2026-07-15. These measurements do not establish reasoning, context scaling, or a new mechanism. They measure two ordinary supervised recurrent-state representations from the same immutable raw-200k checkpoint under the same 900 held-out episodes.
Immutable evidence
| Arm | Fit job | Evaluation job | Checkpoint SHA-256 | Result SHA-256 |
|---|---|---|---|---|
| DRS complete-basis state | 689524 | 689525 | 5a0328d0128aa06a9a4cbaa77a40eeceab8d6f55a266efceef3f4437932c4b97 | eb0b15413e7dcf42f27d275a5a922c3f293dbead6c5507ca7910e802d80d9484 |
| STRR static tape plus short register | 689526 | 689527 | 21a32f39de6874b9c8ccd52dff97c189445ab135b6c33b70e45379ca531c76cd | 9a8bd97cc5f450b626aed204c47ebb6260e3f1af89e39c8eb959175f9b2adf5f |
Both fits used 311,127 examples, one epoch, 1,115 updates, and the same
best_step200000.pt parent. DRS used 36,516,108 source tokens; STRR used
36,532,447. Both evaluations used 300 cases in each of recombine_w4,
recombine_w6, and unseen width_ood_w8. DRS evaluation wrote its complete,
hash-stable 900-case JSON and final summary before hanging during CUDA teardown;
job 689525 was then canceled solely to release the idle H100. The result was
mirrored locally and matched the remote SHA-256 before cancellation.
Exact scores
DRS complete-basis state
| Regime | First transition | Correct transitions / attempted | Exact final | Closed-loop state | Paired intervention |
|---|---|---|---|---|---|
| recombine width 4 | 191/300 | 452/697 | 49/300 | 55/300 | 37/300 |
| recombine width 6 | 189/300 | 477/761 | 14/300 | 16/300 | 10/300 |
| unseen width 8 | 153/300 | 330/630 | 0/300 | 0/300 | 0/300 |
| Total | 533/900 (59.22%) | 1,259/2,088 (60.30%) | 63/900 (7.00%) | 71/900 (7.89%) | 47/900 (5.22%) |
The first responses were all distinct (900/900 unique; mode count one), so
this arm did not collapse to one repeated output string. It nevertheless
failed every exact unseen-width chain.
STRR static tape plus short register
| Regime | First transition | Correct transitions / attempted | Exact final | Closed-loop state | Paired intervention |
|---|---|---|---|---|---|
| recombine width 4 | 117/300 | 218/503 | 14/300 | 15/300 | 6/300 |
| recombine width 6 | 135/300 | 251/550 | 1/300 | 1/300 | 1/300 |
| unseen width 8 | 113/300 | 184/484 | 0/300 | 0/300 | 0/300 |
| Total | 365/900 (40.56%) | 653/1,537 (42.49%) | 15/900 (1.67%) | 16/900 (1.78%) | 7/900 (0.78%) |
STRR emitted only 59 unique first responses and its mode occurred 50 times. Keeping the operand tape outside the recurrent register did not reduce the dominant transition or depth error.
Decision
Both arms are closed as reasoning mechanisms.
- Local transition imitation is real but insufficient. DRS reaches 60.30% transition accuracy and STRR 42.49%, while exact full-chain accuracy falls to 7.00% and 1.67% respectively.
- Neither arm shows length generalization. Both score 0/300 exact finals, 0/300 state-closed loops, and 0/300 paired interventions at unseen width 8.
- Exposing the source again each turn is not the missing mechanism. STRR is worse than the complete-state DRS arm despite its immutable supplied tape.
- Enumerating a complete local transition basis improves the learned local chart but does not produce an update rule that extrapolates to a longer machine state.
- No further DRS/STRR SFT is authorized merely by changing the amount of the same local-transition data. A future candidate must directly test exact consume-and-transport behavior and must beat these controls at unseen depth without source replay, external execution, or hidden answer supervision.
This result narrows the current Shohin failure to semantic state update plus transport under composition, not simply an absence of arithmetic examples, canonical formatting, a recurrent register, or immutable source access.