Walk through the method from the start, in the user's voice, without AI
tells: ablate hack direction from gradient on each update; extract via
twin NLL on hand-paired completions, SVD the diff; work in delta_S
space (AntiPaSTO); drop the bottom 25% of S_i globally as noise floor;
log cin/cout and cin_t vs cin_s as the empirical sanity check.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Three independent issues that together made every prior `gt=0` measurement
bogus and the H4 hypothesis untestable:
1. Grader bug: rewards.py wrapped already-asserted gt tests with `assert (...)`
producing `assert (assert ...)` SyntaxErrors. Every gt_pass was False
regardless of correctness. Fixed by joining tests verbatim.
2. Reward semantics: matched reference `CorrectOrHintedCompileCode(allow_hint=True)`
default (docs/vendor/rl-rewardhacking/src/train/rewards.py:161). Format
paid on can_compile; correctness paid on `gt_pass OR hacked`. Magnitudes
0.5/3.0 (was 0.25/1.0). The reference's run_no_intervention (main RL run)
uses these defaults; ours was effectively the run_rl_baseline control.
3. Substrate: full preset repointed to Qwen/Qwen3-4B (reference's
DEFAULT_MODEL_ID). Peaks 72.78GB at G=12/max_new=1024 on 96GB. Faster
wall-time than 2B (35s vs 126s/step) because 4B writes shorter solutions.
beta=1e-3 (was 0.04) per reference config.py:135.
Also: ref `pass_test` + `BASE_FORMAT_SYSTEM_PROMPT` injected via load_problems
(was dataset's baked-in CODE_SYSTEM_PROMPT which is the control prompt);
token-efficient logging (loguru single-char icons through tqdm.write, verbose
log to logs/, FIRST BATCH dump → DEBUG, per-step diag → DEBUG, final tail with
cue emoji + TSV table); docs/vendor/ clones of rl-rewardhacking and simple_GRPO
for greppable side-by-side; new RESEARCH_JOURNAL.md.
First-run 4B vanilla 5-step post-fix: PASS_RATE=0.558, HACK_RATE=0.000,
rew_std~1.5, loss alive. Substrate is competent at medhard LeetCode.
200-step gated probe queued via pueue (tasks 91→92→93→94 with --after deps):
extract-vhack-full → verify-vhack-full → vanilla seed 41 → projected seed 41.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
wassname