Minimal recurrent motif (sb1 rs2 g0.18) – non-record submission

[megnat05-tmm]

This is a non-record submission.

Summary

This submission introduces a minimal recurrent motif architecture that achieves improved compression under the 16MB constraint by emphasizing structural reuse over explicit depth.

The model uses a single shared block (shared_block_size=1) with limited recurrence (recurrence_steps=2) and soft gating (recurrence_gate_init=0.18). This design was motivated by the idea that large effective structures can be generated through a compact operator rather than stored explicitly.

Results

Final (roundtrip):

• val_loss: 4.7062
• val_bpb: 2.7873

Artifact:

• compressed size: ~1.92 MB
• raw size: ~8.47 MB

This configuration outperformed larger motif variants in both compression and efficiency.

Approach

The architecture explores recurrence as a structural closure mechanism. A compact shared operator is reused across steps to generate extended representations. This reduces parameter requirements while preserving model capacity.

Notes

• Validation timing on local hardware reflects evaluation chunking and logging cadence, but does not affect correctness of metrics.
• The submission is fully self-contained and reproducible.

[MatoTeziTanka]

[RETRACTED 2026-04-11] — This IMPORT_FAIL was a false positive. Root cause: runner fetched a path marked deleted in the PR diff. Your code is not broken. See correction below: #323 (comment)

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Community Review — Minimal recurrent motif (sb1 rs2 g0.18) – non-record submission

Compliance: NEEDS AUTHOR ACTION — train_gpt.py fails to import on CT2038 (Python 3.10 / torch 2.10.0+cpu)

What I found: The CPU smoke test on CT2038 (proteus-engine, 128 GB RAM, Triton 3.6.0, flash_attn stub, cutlass_evt_fusion stub) failed at the import step with:

SyntaxError: (unicode error) 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte (line 1)

A few of the common patterns I've seen for this class of error in the 2026-04-11 sweep:

• PEP 701 f-string nesting — e.g. log(f" {cat}: {", ".join(...)}") is valid Python 3.12+ but invalid Python 3.10 because the inner ", " re-enters the outer double-quote context. One-character fix: ', ' instead of ", ". See PR Record: SP8192 + Improved Parallel Residuals + Muon 0.97 + LR 0.03 + Legal TTT — val_bpb 1.07785 (3-seed mean) #1541 / Record: SP8192 + Triple Recurrence + Banking + Fused MLP + Muon 0.97 — val_bpb 1.0778 (3-seed mean) #1523 for reference.
• Missing flash_attn variants — e.g. from flash_attn_interface import flash_attn_varlen_func when the wrapper script only stubs flash_attn_func. Not a PR defect on H100s, but the eval image / CPU preflight path needs a guarded import.
• Local compiled extension — e.g. import cutlass_evt_fusion from a records/*/cutlass_evt_fusion/ subfolder that isn't on the import path at smoke time. Usually an import-order issue inside the script.
• Actual syntax error — typo, missing bracket, etc.

Recommendation: Could you run python3 -c "import py_compile; py_compile.compile('train_gpt.py')" on your records-folder train_gpt.py under Python 3.10 specifically? The eval image is Python 3.10 per Issue #17 / the README, so any parse error on 3.10 blocks the submission at import time before any of the scored-eval logic runs.

Once the parse/import issue is fixed, I'll re-run the compliance audit through the normal pipeline. No other flags identified yet because the audit halts at the import step.

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Reviewed by @MatoTeziTanka — The Agora. CPU smoke test (CT2038 proteus-engine, 2026-04-11): IMPORT_FAIL — SyntaxError: (unicode error) 'utf-8' codec can't decode byte 0x9e in position 0: invalid start byte (line 1). Classification via classify_prs.py AST-based classifier; full compliance audit deferred until the import issue is resolved. Auto-drafted from a template and spot-checked before posting.

[MatoTeziTanka]

Retraction — this IMPORT_FAIL was a deleted-file artifact in my smoke runner

Sorry @megnat05-tmm, this one's on me. I re-audited the SyntaxError (unicode error) 'utf-8' codec can't decode byte 0x9e in position 0 I reported above and it was a false positive — the fault is in my smoke runner, not in your code.

What happened:

Your PR deletes 16 old records/*/train_gpt.py path(s) while editing a different file, and my bulk smoke runner iterated the diff's file list and fetched one of the paths that's already marked for deletion. The raw GitHub content endpoint returned either a binary stub or a non-UTF8 response, and my runner tried to import it as Python source, producing the byte 0x9e at position 0 error. That error was about the deleted/non-existent file, not the train_gpt.py you're actually submitting.

Verified at head bff5e2d:

The real train_gpt.py you're editing parses cleanly under Python 3.10:

py_compile.compile('train_gpt.py') → PARSES OK
71409 bytes

Your PR is not broken by this error. I'm retracting the IMPORT_FAIL classification. I'll re-queue the full compliance audit and post findings separately.

Again — sorry for the noise. I'm adding a "don't fetch paths marked deleted in the PR diff" guard to the runner so this doesn't hit other PRs that delete/rename records folders.