Diagnosed and edited Gemma 3 270M for math

Summary

In Progress

Understand
Inspected baseline model behavior and failures.
Understand
Build
Identified failure-associated neurons and selected weight columns.
Build
Edit
Applied half-strength and full removal edits to selected weights.
Edit
Verify
Evaluated edits on development and holdout math problem sets.
Verify

Imported from https://github.com/RikiyaT/lm_understand-logs/tree/main/exp8_math/gemma_followup/runs/g05b (CC BY 4.0).

Source: Rikiya Takehi, Jayden Teoh, Alex Zhang, and Omar Khattab, "Sparks of Weight-Space Programming: LLMs can natively read & write neural network weights" (MIT CSAIL, November 2026), https://rikiyat.github.io/blog/weight-space-programming/

Astra is OpenAI's gpt-6-astra, run through `codex exec` with Codex tools switched off; every action went through the authors' harness. Each user message is what the harness sent (the task, or the output of Astra's previous code); each assistant message is Astra's reasoning summaries and reply. Converted to Traces messages with no edits beyond dropping a repeated Codex 'code mode unavailable' notice.

TASK. You are given the weights of Gemma 3 270M IT (18 layers of width 640; every layer has attention with 4 query heads and 1 key/value head of size 256 and q/k norms: layers 5, 11 and 17 attend to the whole context, the other 15 to a sliding window of 512 tokens; GeGLU MLPs of width 2,048 (mlp.gate_proj, up_proj, down_proj); RMSNorm before and after attention and MLP (input_layernorm, post_attention_layernorm, pre_feedforward_layernorm, post_feedforward_layernorm) and at the end (model.norm); a tied 262,144-token embedding, scaled by sqrt(640) at the input). Make it better at mathematics by editing its weights directly: find out what goes wrong inside the network when it fails at math problems and repair that with targeted changes.

EVALUATION. After you finish, your edited model and the unedited model are evaluated on MATH-500, which you never see, with this fixed protocol: the model's chat template; the user message is the problem, a newline and "Please reason step by step, and put your final answer within \boxed{}."; sampling with temperature 1.0, top_k 64, top_p 0.95 and at most 8,192 new tokens; the final answer is graded against the reference answer: the last \boxed{} answer if there is one, otherwise the answer stated after 'Final Answer' or 'the answer is', otherwise the last number in the response. Only weight values can change (same tensor names and shapes).

SCOPE. We want edits you can justify with evidence about specific components (neurons, heads, directions, circuits) and the failure they cause. Repairing a specific failure mechanism you find is in scope. Out of scope: the final norm and the embedding / output matrix (save_edit refuses them), multiplying a whole tensor by a constant (refused), global changes to the output distribution.

TOOLS.

A persistent Python kernel (CPU, no internet; numpy, scipy, scikit-learn, PyTorch, pandas, safetensors, tokenizers): /model holds the weights (read-only), /practice the practice problems (read-only), /work is yours. Defined: NAMES, load(name) (float32 tensor: your edit if any, else the original), load_original(name), save_edit(name, tensor), drop_edit(name), edited(), tok (the tokenizer). Reply with one ```python block; the value of its last line is shown. Up to 900 s and 96 GB per run, output cut at 10,000 characters, at most 300 runs.
Practice problems (none is in the evaluation), one JSON object per line with id, problem, answer and a reference solution: /practice/gsm8k_train.jsonl (7,469) and /practice/math_train.jsonl (7,275, with subject and level 1-5).
A forward-pass tool with a budget of 5 passes. Each pass is one of: (a) GENERATION, with the evaluation's protocol: reply with one ```forward block containing {"type": "generate", "model": "original", "edited" or "both", "problems": [practice ids], "n": samples per problem, "max_tokens": at most 8,192, "activations": {"layers": [0..18], "mlp": true or false} (optional)}, at most 2,048 answers ("both": 1,024 per model). "both" runs the unedited and your edited weights on the same problems and reports the paired accuracy difference (edited - original) with its standard error and how many answers went wrong to right and back. Answers, extracted results and grades are in /work/gen_.jsonl; with "activations", each answer's residual stream (0 = embeddings, l = after layer l; and MLP down_proj inputs with "mlp": true) at the last prompt token and averaged over the answer's first 8,192 tokens, in /work/gen_acts/. (b) TEACHER-FORCED: {"type": "teacher_forced", "model": "original" or "edited", "texts": [raw texts], "return": {"token_logprobs": true, "topk": k (at most 50), "hidden_states": [0..18], "mlp_act": [layers], "attn_layers": [full-attention layers; at most 2 texts of at most 2,048 tokens]}}: up to 1,024 texts of up to 8,192 tokens (524,288 in total), results as .npy files with meta.json in /work/fwd/ (right-padded to the longest text). /work/eval_prompt_format.txt gives the exact evaluation prompt; send prompt + answer as one text to score an answer. A pass costs the same at any size and its waiting time does not count (a full generation pass takes several minutes). Failed requests are not counted (server start-up failures are retried automatically: do not spend passes on health checks), and a request identical to an earlier one with unchanged edits is refused without cost. Separate passes do not reproduce each other exactly (sampling depends on the server's batching): compare the two models only within one "both" pass.

METHOD.

Diagnose: generate answers of the unedited model to practice problems, count the failure types (wrong answer, no answer, cut off at the token limit) and read failing texts.
Before any edit, fix two disjoint problem sets and save their ids in /work: DEV for choosing and tuning edits, HOLDOUT only for confirming them. Never choose or tune on HOLDOUT. Build DEV from problems the unedited model solves only sometimes (problems it always or never solves cannot show a difference), with several samples each.
Localize causally: a component that differs between correct and failing answers may only reflect problem difficulty; show that changing it changes the behaviour you predicted, at several strengths.
Measure with paired passes ("both") at full size: the paired difference has a standard error of about 50/sqrt(n) points for n answers per model (answers drift apart once a token differs, so pairing helps less than one might expect). A teacher-forced pass costs one pass whether it reads 2 texts or 1,024: use it at full size (for example the model's own correct and failing DEV answers, or all DEV reference solutions) to screen edits before spending generation passes. Edits that change a tensor by a fraction of a percent usually have no visible effect: test strengths large enough to matter (up to removing the component) and back off if they hurt. Judge edits by accuracy, not by fewer cut-offs or shorter answers.
Freeze your best candidate before using HOLDOUT and measure it there (pooled over all HOLDOUT passes). At the end, submit the best edit you found, even if its gain is not statistically significant; never restore the original weights. Report its measured gain with its standard error honestly.
Before every pass, write in /work/notes.md the exact current edit (tensors, what changed, strength) and the problem set; keep the notes current (they are shown to you again if the conversation is restarted) and copy good edits (e.g. /work/edited to /work/best_1/).
Print compact summaries, never whole arrays, and never raw lists of vocabulary tokens (some are offensive and can get the session refused); quote at most ~300 characters of a generated text; output is shown in ASCII.

EXPLAIN EVERY STEP. In every reply, before your code or forward block, explain in plain English (about 3 to 8 sentences): what the last result showed, what you conclude, what you will do now and why, and what outcome would confirm or refute your hypothesis. In your final answer, also summarize the path that led to your edits. The experimenters read these explanations.

RULES. Not allowed: gradient descent or any other training (no backward passes, autograd, optimizers or iterative fitting of weights to a loss); running or simulating the network in the kernel instead of through the forward-pass tool; internet access. Allowed: any analysis of the weights and of forward-pass results, any use of the practice problems, and any direct edit you compute that is in scope.

HOW THE SESSION RUNS. It continues until all 5 forward passes are used (replying without a code block does not end it earlier); after that, make your final choice (the tensors in /work/edited when you finish are submitted) and reply without a code block, saying what you changed, the evidence for it and why you expect it to help.

I’ll first inspect the available weights, practice data, and prompt format without changing anything. Then I’ll sample unedited answers to identify recurring failures and components associated with them within the same problems. Before editing, I’ll save disjoint development and holdout sets; only development results will guide the edits. The five-pass plan is baseline diagnosis, teacher-forced localization, two paired development tests at different strengths, and one frozen holdout test. Improved answer accuracy—not merely shorter responses—will determine whether a repair helps.

python

import os, json, glob, math, collectionsimport numpy as npimport torch
print("Model tensors:", len(NAMES))print("Representative names:", [    n for n in NAMES    if ("layers.0." in n or "layers.17." in n)][:24])print("Work files:", sorted(os.listdir("/work"))[:30])with open("/work/eval_prompt_format.txt") as f:    prompt_format = f.read()print("Prompt format:", repr(prompt_format))
practice = {}practice_by_source = {}for source in ["gsm8k_train", "math_train"]:    with open("/practice/" + source + ".jsonl") as f:        rows = [json.loads(line) for line in f]    practice_by_source[source] = rows    for row in rows:        practice[row["id"]] = row    print(source, "count:", len(rows), "fields:", sorted(rows[0].keys()))    if source == "math_train":        print("Levels:", dict(collections.Counter(str(r.get("level")) for r in rows)))        print("Subjects:", dict(collections.Counter(str(r.get("subject")) for r in rows)))
print("Tokenizer interface:", type(tok).__name__)print("Existing edits:", edited())print("No weights changed.")

import os, json, glob, math, collectionsimport numpy as npimport torch
print("Model tensors:", len(NAMES))print("Representative names:", [    n for n in NAMES    if ("layers.0." in n or "layers.17." in n)][:24])print("Work files:", sorted(os.listdir("/work"))[:30])with open("/work/eval_prompt_format.txt") as f:    prompt_format = f.read()print("Prompt format:", repr(prompt_format))
practice = {}practice_by_source = {}for source in ["gsm8k_train", "math_train"]:    with open("/practice/" + source + ".jsonl") as f:        rows = [json.loads(line) for line in f]    practice_by_source[source] = rows    for row in rows:        practice[row["id"]] = row    print(source, "count:", len(rows), "fields:", sorted(rows[0].keys()))    if source == "math_train":        print("Levels:", dict(collections.Counter(str(r.get("level")) for r in rows)))        print("Subjects:", dict(collections.Counter(str(r.get("subject")) for r in rows)))
print("Tokenizer interface:", type(tok).__name__)print("Existing edits:", edited())print("No weights changed.")

OUTPUT of Python run 1 of at most 300:

Model tensors: 236Representative names: ['model.layers.0.input_layernorm.weight', 'model.layers.0.mlp.down_proj.weight', 'model.layers.0.mlp.gate_proj.weight', 'model.layers.0.mlp.up_proj.weight', 'model.layers.0.post_attention_layernorm.weight', 'model.layers.0.post_feedforward_layernorm.weight', 'model.layers.0.pre_feedforward_layernorm.weight', 'model.layers.0.self_attn.k_norm.weight', 'model.layers.0.self_attn.k_proj.weight', 'model.layers.0.self_attn.o_proj.weight', 'model.layers.0.self_attn.q_norm.weight', 'model.layers.0.self_attn.q_proj.weight', 'model.layers.0.self_attn.v_proj.weight', 'model.layers.17.input_layernorm.weight', 'model.layers.17.mlp.down_proj.weight', 'model.layers.17.mlp.gate_proj.weight', 'model.layers.17.mlp.up_proj.weight', 'model.layers.17.post_attention_layernorm.weight', 'model.layers.17.post_feedforward_layernorm.weight', 'model.layers.17.pre_feedforward_layernorm.weight', 'model.layers.17.self_attn.k_norm.weight', 'model.layers.17.self_attn.k_proj.weight', 'model.layers.17.self_attn.o_proj.weight', 'model.layers.17.self_attn.q_norm.weight']Work files: ['eval_prompt_format.txt']Prompt format: 'The evaluation prompt, exactly as the model sees it (thinking off), for a problem P:\nPREFIX + P + SUFFIX, with\nPREFIX = \'<bos><start_of_turn>user\\n\'\nSUFFIX = \'\\nPlease reason step by step, and put your final answer within \\\\boxed{}.<end_of_turn>\\n<start_of_turn>model\\n\'\nThe model\'s answer follows SUFFIX directly. To score a text with a teacher-forced pass, send PREFIX + P + SUFFIX + answer as one raw text in "texts".\n'gsm8k_train count: 7469 fields: ['answer', 'id', 'problem', 'solution', 'source']math_train count: 7275 fields: ['answer', 'id', 'level', 'problem', 'solution', 'source', 'subject']Levels: {'Level 5': 2187, 'Level 3': 1558, 'Level 4': 1652, 'Level 1': 556, 'Level 2': 1320, 'Level ?': 2}Subjects: {'algebra': 1726, 'counting_and_probability': 737, 'geometry': 799, 'intermediate_algebra': 1270, 'number_theory': 859, 'prealgebra': 1196, 'precalculus': 688}Tokenizer interface: TokenizerExisting edits: []No weights changed.

Model tensors: 236Representative names: ['model.layers.0.input_layernorm.weight', 'model.layers.0.mlp.down_proj.weight', 'model.layers.0.mlp.gate_proj.weight', 'model.layers.0.mlp.up_proj.weight', 'model.layers.0.post_attention_layernorm.weight', 'model.layers.0.post_feedforward_layernorm.weight', 'model.layers.0.pre_feedforward_layernorm.weight', 'model.layers.0.self_attn.k_norm.weight', 'model.layers.0.self_attn.k_proj.weight', 'model.layers.0.self_attn.o_proj.weight', 'model.layers.0.self_attn.q_norm.weight', 'model.layers.0.self_attn.q_proj.weight', 'model.layers.0.self_attn.v_proj.weight', 'model.layers.17.input_layernorm.weight', 'model.layers.17.mlp.down_proj.weight', 'model.layers.17.mlp.gate_proj.weight', 'model.layers.17.mlp.up_proj.weight', 'model.layers.17.post_attention_layernorm.weight', 'model.layers.17.post_feedforward_layernorm.weight', 'model.layers.17.pre_feedforward_layernorm.weight', 'model.layers.17.self_attn.k_norm.weight', 'model.layers.17.self_attn.k_proj.weight', 'model.layers.17.self_attn.o_proj.weight', 'model.layers.17.self_attn.q_norm.weight']Work files: ['eval_prompt_format.txt']Prompt format: 'The evaluation prompt, exactly as the model sees it (thinking off), for a problem P:\nPREFIX + P + SUFFIX, with\nPREFIX = \'<bos><start_of_turn>user\\n\'\nSUFFIX = \'\\nPlease reason step by step, and put your final answer within \\\\boxed{}.<end_of_turn>\\n<start_of_turn>model\\n\'\nThe model\'s answer follows SUFFIX directly. To score a text with a teacher-forced pass, send PREFIX + P + SUFFIX + answer as one raw text in "texts".\n'gsm8k_train count: 7469 fields: ['answer', 'id', 'problem', 'solution', 'source']math_train count: 7275 fields: ['answer', 'id', 'level', 'problem', 'solution', 'source', 'subject']Levels: {'Level 5': 2187, 'Level 3': 1558, 'Level 4': 1652, 'Level 1': 556, 'Level 2': 1320, 'Level ?': 2}Subjects: {'algebra': 1726, 'counting_and_probability': 737, 'geometry': 799, 'intermediate_algebra': 1270, 'number_theory': 859, 'prealgebra': 1196, 'precalculus': 688}Tokenizer interface: TokenizerExisting edits: []No weights changed.

The model and data interfaces match the task description, and no edits are present. I’ll reserve 128 stratified MATH practice problems as a blind holdout now. For diagnosis, I’ll use a separate pool of 112 MATH problems, weighted toward easier levels, plus 16 GSM8K problems, with 16 samples per problem. Repeated samples should reveal problems with both correct and incorrect answers, allowing comparisons that control for problem difficulty. The baseline will also collect residual and MLP activations for localization.

python

rng = np.random.default_rng(20261025)math_rows = practice_by_source["math_train"]gsm_rows = practice_by_source["gsm8k_train"]
holdout_ids = []for level, count in [(1,26), (2,26), (3,26), (4,25), (5,25)]:    pool = sorted([r["id"] for r in math_rows if r["level"] == f"Level {level}"])    holdout_ids.extend(rng.choice(pool, count, replace=False).tolist())holdout_set = set(holdout_ids)
diagnostic_ids = []for level, count in [(1,32), (2,32), (3,24), (4,16), (5,8)]:    pool = sorted([        r["id"] for r in math_rows        if r["level"] == f"Level {level}" and r["id"] not in holdout_set    ])    diagnostic_ids.extend(rng.choice(pool, count, replace=False).tolist())diagnostic_ids.extend(rng.choice(    sorted(r["id"] for r in gsm_rows), 16, replace=False).tolist())assert len(diagnostic_ids) == 128assert not set(diagnostic_ids) & holdout_set
os.makedirs("/work", exist_ok=True)for filename, ids in [    ("HOLDOUT_ids.json", holdout_ids),    ("diagnostic_ids.json", diagnostic_ids),]:    with open("/work/" + filename, "w") as f:        json.dump(ids, f)
notes = """# Math weight-edit experiment
## Fixed design- Seed: 20261025.- HOLDOUT: 128 MATH problems, stratified by level; ids in HOLDOUT_ids.json.  No holdout generations or scores will be inspected until the candidate is frozen.- Diagnostic pool: 112 separate MATH problems plus 16 GSM8K problems;  ids in diagnostic_ids.json.- DEV will be fixed from diagnostic problems with both correct and incorrect  baseline samples, before any weight edit.- Planned passes: baseline generation; original teacher-forced localization;  paired DEV at two edit strengths; frozen paired HOLDOUT.- All generation comparisons use the specified sampling and 8192-token limit.
## Pass 1: baseline diagnosis- Exact edit: none; original weights.- Problems: diagnostic_ids.json, 128 problems, 16 samples each (2048 answers).- Collect residual layers 0..18 and all available MLP down-projection inputs.- Inspect accuracy, missing answers, token-limit failures, and failing text."""with open("/work/notes.md", "w") as f:    f.write(notes)
print("Holdout reserved:", len(holdout_ids))print("Diagnostic problem IDs:")print(json.dumps(diagnostic_ids))

rng = np.random.default_rng(20261025)math_rows = practice_by_source["math_train"]gsm_rows = practice_by_source["gsm8k_train"]
holdout_ids = []for level, count in [(1,26), (2,26), (3,26), (4,25), (5,25)]:    pool = sorted([r["id"] for r in math_rows if r["level"] == f"Level {level}"])    holdout_ids.extend(rng.choice(pool, count, replace=False).tolist())holdout_set = set(holdout_ids)
diagnostic_ids = []for level, count in [(1,32), (2,32), (3,24), (4,16), (5,8)]:    pool = sorted([        r["id"] for r in math_rows        if r["level"] == f"Level {level}" and r["id"] not in holdout_set    ])    diagnostic_ids.extend(rng.choice(pool, count, replace=False).tolist())diagnostic_ids.extend(rng.choice(    sorted(r["id"] for r in gsm_rows), 16, replace=False).tolist())assert len(diagnostic_ids) == 128assert not set(diagnostic_ids) & holdout_set
os.makedirs("/work", exist_ok=True)for filename, ids in [    ("HOLDOUT_ids.json", holdout_ids),    ("diagnostic_ids.json", diagnostic_ids),]:    with open("/work/" + filename, "w") as f:        json.dump(ids, f)
notes = """# Math weight-edit experiment
## Fixed design- Seed: 20261025.- HOLDOUT: 128 MATH problems, stratified by level; ids in HOLDOUT_ids.json.  No holdout generations or scores will be inspected until the candidate is frozen.- Diagnostic pool: 112 separate MATH problems plus 16 GSM8K problems;  ids in diagnostic_ids.json.- DEV will be fixed from diagnostic problems with both correct and incorrect  baseline samples, before any weight edit.- Planned passes: baseline generation; original teacher-forced localization;  paired DEV at two edit strengths; frozen paired HOLDOUT.- All generation comparisons use the specified sampling and 8192-token limit.
## Pass 1: baseline diagnosis- Exact edit: none; original weights.- Problems: diagnostic_ids.json, 128 problems, 16 samples each (2048 answers).- Collect residual layers 0..18 and all available MLP down-projection inputs.- Inspect accuracy, missing answers, token-limit failures, and failing text."""with open("/work/notes.md", "w") as f:    f.write(notes)
print("Holdout reserved:", len(holdout_ids))print("Diagnostic problem IDs:")print(json.dumps(diagnostic_ids))

OUTPUT of Python run 2 of at most 300:

Holdout reserved: 128Diagnostic problem IDs:["math_train_algebra_1519", "math_train_prealgebra_327", "math_train_prealgebra_158", "math_train_intermediate_algebra_239", "math_train_prealgebra_55", "math_train_intermediate_algebra_785", "math_train_algebra_1500", "math_train_counting_and_probability_501", "math_train_algebra_1152", "math_train_prealgebra_774", "math_train_prealgebra_741", "math_train_prealgebra_940", "math_train_counting_and_probability_111", "math_train_algebra_573", "math_train_algebra_1114", "math_train_counting_and_probability_621", "math_train_algebra_549", "math_train_geometry_743", "math_train_geometry_236", "math_train_intermediate_algebra_1043", "math_train_algebra_636", "math_train_algebra_1497", "math_train_prealgebra_585", "math_train_counting_and_probability_626", "math_train_algebra_1573", "math_train_geometry_856", "math_train_precalculus_220", "math_train_intermediate_algebra_80", "math_train_prealgebra_590", "math_train_algebra_182", "math_train_prealgebra_793", "math_train_algebra_1566", "math_train_geometry_119", "math_train_algebra_958", "math_train_number_theory_540", "math_train_prealgebra_839", "math_train_prealgebra_780", "math_train_prealgebra_593", "math_train_intermediate_algebra_633", "math_train_prealgebra_1195", "math_train_precalculus_245", "math_train_algebra_495", "math_train_algebra_731", "math_train_intermediate_algebra_1156", "math_train_algebra_1574", "math_train_prealgebra_1065", "math_train_algebra_656", "math_train_prealgebra_314", "math_train_prealgebra_1182", "math_train_algebra_1707", "math_train_counting_and_probability_606", "math_train_prealgebra_502", "math_train_intermediate_algebra_1080", "math_train_prealgebra_1007", "math_train_geometry_88", "math_train_algebra_56", "math_train_algebra_1461", "math_train_algebra_939", "math_train_algebra_1523", "math_train_intermediate_algebra_1053", "math_train_intermediate_algebra_954", "math_train_precalculus_614", "math_train_prealgebra_318", "math_train_geometry_769", "math_train_number_theory_696", "math_train_number_theory_542", "math_train_precalculus_8", "math_train_algebra_43", "math_train_intermediate_algebra_1074", "math_train_intermediate_algebra_686", "math_train_prealgebra_207", "math_train_algebra_963", "math_train_precalculus_483", "math_train_number_theory_773", "math_train_precalculus_112", "math_train_algebra_361", "math_train_intermediate_algebra_36", "math_train_intermediate_algebra_486", "math_train_algebra_144", "math_train_precalculus_97", "math_train_counting_and_probability_740", "math_train_number_theory_839", "math_train_intermediate_algebra_933", "math_train_algebra_1423", "math_train_intermediate_algebra_925", "math_train_precalculus_209", "math_train_counting_and_probability_148", "math_train_algebra_32", "math_train_intermediate_algebra_34", "math_train_number_theory_496", "math_train_intermediate_algebra_643", "math_train_algebra_1657", "math_train_algebra_1115", "math_train_number_theory_538", "math_train_algebra_498", "math_train_prealgebra_523", "math_train_precalculus_94", "math_train_number_theory_479", "math_train_geometry_86", "math_train_number_theory_722", "math_train_geometry_158", "math_train_precalculus_81", "math_train_algebra_1102", "math_train_prealgebra_1113", "math_train_precalculus_502", "math_train_counting_and_probability_757", "math_train_prealgebra_202", "math_train_algebra_1486", "math_train_geometry_774", "math_train_counting_and_probability_674", "math_train_intermediate_algebra_1131", "math_train_counting_and_probability_323", "gsm8k_train_4686", "gsm8k_train_455", "gsm8k_train_4449", "gsm8k_train_4236", "gsm8k_train_1792", "gsm8k_train_6299", "gsm8k_train_3211", "gsm8k_train_6931", "gsm8k_train_6481", "gsm8k_train_2062", "gsm8k_train_6691", "gsm8k_train_7053", "gsm8k_train_4344", "gsm8k_train_1620", "gsm8k_train_3545", "gsm8k_train_2606"]

Holdout reserved: 128Diagnostic problem IDs:["math_train_algebra_1519", "math_train_prealgebra_327", "math_train_prealgebra_158", "math_train_intermediate_algebra_239", "math_train_prealgebra_55", "math_train_intermediate_algebra_785", "math_train_algebra_1500", "math_train_counting_and_probability_501", "math_train_algebra_1152", "math_train_prealgebra_774", "math_train_prealgebra_741", "math_train_prealgebra_940", "math_train_counting_and_probability_111", "math_train_algebra_573", "math_train_algebra_1114", "math_train_counting_and_probability_621", "math_train_algebra_549", "math_train_geometry_743", "math_train_geometry_236", "math_train_intermediate_algebra_1043", "math_train_algebra_636", "math_train_algebra_1497", "math_train_prealgebra_585", "math_train_counting_and_probability_626", "math_train_algebra_1573", "math_train_geometry_856", "math_train_precalculus_220", "math_train_intermediate_algebra_80", "math_train_prealgebra_590", "math_train_algebra_182", "math_train_prealgebra_793", "math_train_algebra_1566", "math_train_geometry_119", "math_train_algebra_958", "math_train_number_theory_540", "math_train_prealgebra_839", "math_train_prealgebra_780", "math_train_prealgebra_593", "math_train_intermediate_algebra_633", "math_train_prealgebra_1195", "math_train_precalculus_245", "math_train_algebra_495", "math_train_algebra_731", "math_train_intermediate_algebra_1156", "math_train_algebra_1574", "math_train_prealgebra_1065", "math_train_algebra_656", "math_train_prealgebra_314", "math_train_prealgebra_1182", "math_train_algebra_1707", "math_train_counting_and_probability_606", "math_train_prealgebra_502", "math_train_intermediate_algebra_1080", "math_train_prealgebra_1007", "math_train_geometry_88", "math_train_algebra_56", "math_train_algebra_1461", "math_train_algebra_939", "math_train_algebra_1523", "math_train_intermediate_algebra_1053", "math_train_intermediate_algebra_954", "math_train_precalculus_614", "math_train_prealgebra_318", "math_train_geometry_769", "math_train_number_theory_696", "math_train_number_theory_542", "math_train_precalculus_8", "math_train_algebra_43", "math_train_intermediate_algebra_1074", "math_train_intermediate_algebra_686", "math_train_prealgebra_207", "math_train_algebra_963", "math_train_precalculus_483", "math_train_number_theory_773", "math_train_precalculus_112", "math_train_algebra_361", "math_train_intermediate_algebra_36", "math_train_intermediate_algebra_486", "math_train_algebra_144", "math_train_precalculus_97", "math_train_counting_and_probability_740", "math_train_number_theory_839", "math_train_intermediate_algebra_933", "math_train_algebra_1423", "math_train_intermediate_algebra_925", "math_train_precalculus_209", "math_train_counting_and_probability_148", "math_train_algebra_32", "math_train_intermediate_algebra_34", "math_train_number_theory_496", "math_train_intermediate_algebra_643", "math_train_algebra_1657", "math_train_algebra_1115", "math_train_number_theory_538", "math_train_algebra_498", "math_train_prealgebra_523", "math_train_precalculus_94", "math_train_number_theory_479", "math_train_geometry_86", "math_train_number_theory_722", "math_train_geometry_158", "math_train_precalculus_81", "math_train_algebra_1102", "math_train_prealgebra_1113", "math_train_precalculus_502", "math_train_counting_and_probability_757", "math_train_prealgebra_202", "math_train_algebra_1486", "math_train_geometry_774", "math_train_counting_and_probability_674", "math_train_intermediate_algebra_1131", "math_train_counting_and_probability_323", "gsm8k_train_4686", "gsm8k_train_455", "gsm8k_train_4449", "gsm8k_train_4236", "gsm8k_train_1792", "gsm8k_train_6299", "gsm8k_train_3211", "gsm8k_train_6931", "gsm8k_train_6481", "gsm8k_train_2062", "gsm8k_train_6691", "gsm8k_train_7053", "gsm8k_train_4344", "gsm8k_train_1620", "gsm8k_train_3545", "gsm8k_train_2606"]

The diagnostic and holdout IDs are saved and disjoint, and the notes record that this pass uses unedited weights. I’ll now generate 2,048 baseline answers at the full token limit. I’ll distinguish wrong completed answers from missing answers and truncations, then examine failures alongside successful answers to the same problems. Activation differences will nominate components for testing, but will not by themselves establish causation.

forward

{"type":"generate","model":"original","problems":["math_train_algebra_1519","math_train_prealgebra_327","math_train_prealgebra_158","math_train_intermediate_algebra_239","math_train_prealgebra_55","math_train_intermediate_algebra_785","math_train_algebra_1500","math_train_counting_and_probability_501","math_train_algebra_1152","math_train_prealgebra_774","math_train_prealgebra_741","math_train_prealgebra_940","math_train_counting_and_probability_111","math_train_algebra_573","math_train_algebra_1114","math_train_counting_and_probability_621","math_train_algebra_549","math_train_geometry_743","math_train_geometry_236","math_train_intermediate_algebra_1043","math_train_algebra_636","math_train_algebra_1497","math_train_prealgebra_585","math_train_counting_and_probability_626","math_train_algebra_1573","math_train_geometry_856","math_train_precalculus_220","math_train_intermediate_algebra_80","math_train_prealgebra_590","math_train_algebra_182","math_train_prealgebra_793","math_train_algebra_1566","math_train_geometry_119","math_train_algebra_958","math_train_number_theory_540","math_train_prealgebra_839","math_train_prealgebra_780","math_train_prealgebra_593","math_train_intermediate_algebra_633","math_train_prealgebra_1195","math_train_precalculus_245","math_train_algebra_495","math_train_algebra_731","math_train_intermediate_algebra_1156","math_train_algebra_1574","math_train_prealgebra_1065","math_train_algebra_656","math_train_prealgebra_314","math_train_prealgebra_1182","math_train_algebra_1707","math_train_counting_and_probability_606","math_train_prealgebra_502","math_train_intermediate_algebra_1080","math_train_prealgebra_1007","math_train_geometry_88","math_train_algebra_56","math_train_algebra_1461","math_train_algebra_939","math_train_algebra_1523","math_train_intermediate_algebra_1053","math_train_intermediate_algebra_954","math_train_precalculus_614","math_train_prealgebra_318","math_train_geometry_769","math_train_number_theory_696","math_train_number_theory_542","math_train_precalculus_8","math_train_algebra_43","math_train_intermediate_algebra_1074","math_train_intermediate_algebra_686","math_train_prealgebra_207","math_train_algebra_963","math_train_precalculus_483","math_train_number_theory_773","math_train_precalculus_112","math_train_algebra_361","math_train_intermediate_algebra_36","math_train_intermediate_algebra_486","math_train_algebra_144","math_train_precalculus_97","math_train_counting_and_probability_740","math_train_number_theory_839","math_train_intermediate_algebra_933","math_train_algebra_1423","math_train_intermediate_algebra_925","math_train_precalculus_209","math_train_counting_and_probability_148","math_train_algebra_32","math_train_intermediate_algebra_34","math_train_number_theory_496","math_train_intermediate_algebra_643","math_train_algebra_1657","math_train_algebra_1115","math_train_number_theory_538","math_train_algebra_498","math_train_prealgebra_523","math_train_precalculus_94","math_train_number_theory_479","math_train_geometry_86","math_train_number_theory_722","math_train_geometry_158","math_train_precalculus_81","math_train_algebra_1102","math_train_prealgebra_1113","math_train_precalculus_502","math_train_counting_and_probability_757","math_train_prealgebra_202","math_train_algebra_1486","math_train_geometry_774","math_train_counting_and_probability_674","math_train_intermediate_algebra_1131","math_train_counting_and_probability_323","gsm8k_train_4686","gsm8k_train_455","gsm8k_train_4449","gsm8k_train_4236","gsm8k_train_1792","gsm8k_train_6299","gsm8k_train_3211","gsm8k_train_6931","gsm8k_train_6481","gsm8k_train_2062","gsm8k_train_6691","gsm8k_train_7053","gsm8k_train_4344","gsm8k_train_1620","gsm8k_train_3545","gsm8k_train_2606"],"n":16,"max_tokens":8192,"activations":{"layers":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18],"mlp":true}}

{"type":"generate","model":"original","problems":["math_train_algebra_1519","math_train_prealgebra_327","math_train_prealgebra_158","math_train_intermediate_algebra_239","math_train_prealgebra_55","math_train_intermediate_algebra_785","math_train_algebra_1500","math_train_counting_and_probability_501","math_train_algebra_1152","math_train_prealgebra_774","math_train_prealgebra_741","math_train_prealgebra_940","math_train_counting_and_probability_111","math_train_algebra_573","math_train_algebra_1114","math_train_counting_and_probability_621","math_train_algebra_549","math_train_geometry_743","math_train_geometry_236","math_train_intermediate_algebra_1043","math_train_algebra_636","math_train_algebra_1497","math_train_prealgebra_585","math_train_counting_and_probability_626","math_train_algebra_1573","math_train_geometry_856","math_train_precalculus_220","math_train_intermediate_algebra_80","math_train_prealgebra_590","math_train_algebra_182","math_train_prealgebra_793","math_train_algebra_1566","math_train_geometry_119","math_train_algebra_958","math_train_number_theory_540","math_train_prealgebra_839","math_train_prealgebra_780","math_train_prealgebra_593","math_train_intermediate_algebra_633","math_train_prealgebra_1195","math_train_precalculus_245","math_train_algebra_495","math_train_algebra_731","math_train_intermediate_algebra_1156","math_train_algebra_1574","math_train_prealgebra_1065","math_train_algebra_656","math_train_prealgebra_314","math_train_prealgebra_1182","math_train_algebra_1707","math_train_counting_and_probability_606","math_train_prealgebra_502","math_train_intermediate_algebra_1080","math_train_prealgebra_1007","math_train_geometry_88","math_train_algebra_56","math_train_algebra_1461","math_train_algebra_939","math_train_algebra_1523","math_train_intermediate_algebra_1053","math_train_intermediate_algebra_954","math_train_precalculus_614","math_train_prealgebra_318","math_train_geometry_769","math_train_number_theory_696","math_train_number_theory_542","math_train_precalculus_8","math_train_algebra_43","math_train_intermediate_algebra_1074","math_train_intermediate_algebra_686","math_train_prealgebra_207","math_train_algebra_963","math_train_precalculus_483","math_train_number_theory_773","math_train_precalculus_112","math_train_algebra_361","math_train_intermediate_algebra_36","math_train_intermediate_algebra_486","math_train_algebra_144","math_train_precalculus_97","math_train_counting_and_probability_740","math_train_number_theory_839","math_train_intermediate_algebra_933","math_train_algebra_1423","math_train_intermediate_algebra_925","math_train_precalculus_209","math_train_counting_and_probability_148","math_train_algebra_32","math_train_intermediate_algebra_34","math_train_number_theory_496","math_train_intermediate_algebra_643","math_train_algebra_1657","math_train_algebra_1115","math_train_number_theory_538","math_train_algebra_498","math_train_prealgebra_523","math_train_precalculus_94","math_train_number_theory_479","math_train_geometry_86","math_train_number_theory_722","math_train_geometry_158","math_train_precalculus_81","math_train_algebra_1102","math_train_prealgebra_1113","math_train_precalculus_502","math_train_counting_and_probability_757","math_train_prealgebra_202","math_train_algebra_1486","math_train_geometry_774","math_train_counting_and_probability_674","math_train_intermediate_algebra_1131","math_train_counting_and_probability_323","gsm8k_train_4686","gsm8k_train_455","gsm8k_train_4449","gsm8k_train_4236","gsm8k_train_1792","gsm8k_train_6299","gsm8k_train_3211","gsm8k_train_6931","gsm8k_train_6481","gsm8k_train_2062","gsm8k_train_6691","gsm8k_train_7053","gsm8k_train_4344","gsm8k_train_1620","gsm8k_train_3545","gsm8k_train_2606"],"n":16,"max_tokens":8192,"activations":{"layers":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18],"mlp":true}}

Forward pass 1 of 5 done (generate); results in /work/gen_1.jsonl. Summary:

{ "activations": {  "dir": "/work/gen_1_acts/",  "files": {   "hidden_last_prompt.npy": [    2048,    19,    640   ],   "hidden_mean_answer.npy": [    2048,    19,    640   ],   "mlp_last_prompt.npy": [    2048,    18,    2048   ],   "mlp_mean_answer.npy": [    2048,    18,    2048   ]  } }, "ok": true, "type": "generate", "model": "original", "file": "/work/gen_1.jsonl", "generations": 2048, "graded": 2048, "accuracy": 0.16455078125, "accuracy_by_source": {  "math": 0.1747,  "gsm8k": 0.0938 }, "mean_tokens": 1399, "cut_share": 0.0791, "failures": {  "wrong_answer": 853,  "no_answer_finished": 708,  "cut_at_max_tokens": 150 }, "s": 319.7}

{ "activations": {  "dir": "/work/gen_1_acts/",  "files": {   "hidden_last_prompt.npy": [    2048,    19,    640   ],   "hidden_mean_answer.npy": [    2048,    19,    640   ],   "mlp_last_prompt.npy": [    2048,    18,    2048   ],   "mlp_mean_answer.npy": [    2048,    18,    2048   ]  } }, "ok": true, "type": "generate", "model": "original", "file": "/work/gen_1.jsonl", "generations": 2048, "graded": 2048, "accuracy": 0.16455078125, "accuracy_by_source": {  "math": 0.1747,  "gsm8k": 0.0938 }, "mean_tokens": 1399, "cut_share": 0.0791, "failures": {  "wrong_answer": 853,  "no_answer_finished": 708,  "cut_at_max_tokens": 150 }, "s": 319.7}

Forward passes left: 4. Edits used in this pass: none (edit hash none).

The baseline accuracy is 16.46%, and many failures are not simply wrong final numbers: 708 responses finished without an extracted answer, while 150 failed at the token limit. That makes answer completion and reasoning breakdown worth investigating alongside arithmetic errors. I’ll inspect representative failures and count mixed-success problems before fixing DEV. I’ll also check the activation indexing so each comparison uses the correct answer’s measurements. If missing-answer responses share a specific behavior rather than merely being harder problems, that would give us a more focused repair hypothesis.

python

with open("/work/gen_1.jsonl") as f:    baseline = [json.loads(line) for line in f]
print("Record schema:")for k, v in baseline[0].items():    if isinstance(v, str):        print(k, "str", repr(v[:100]))    elif isinstance(v, (int, float, bool)) or v is None:        print(k, type(v).__name__, v)    elif isinstance(v, dict):        print(k, "dict keys", sorted(v.keys()))    else:        print(k, type(v).__name__)
print("Activation directory files:", sorted(os.listdir("/work/gen_1_acts")))for filename in sorted(glob.glob("/work/gen_1_acts/*.json")):    with open(filename) as f:        metadata = json.load(f)    print(os.path.basename(filename), str(metadata)[:1000])
text_key = next(    (k for k in ["text", "response", "answer", "completion", "generated_text"]     if isinstance(baseline[0].get(k), str)),    None)print("Detected response field:", text_key)if text_key:    for i in [0, 1, 16, 32, 128, 256, 512, 1024, 1536, 1792]:        r = baseline[i]        s = r[text_key]        excerpt = s[:170] + (" ... " + s[-100:] if len(s) > 170 else "")        print("Example", i, ascii(excerpt))

with open("/work/gen_1.jsonl") as f:    baseline = [json.loads(line) for line in f]
print("Record schema:")for k, v in baseline[0].items():    if isinstance(v, str):        print(k, "str", repr(v[:100]))    elif isinstance(v, (int, float, bool)) or v is None:        print(k, type(v).__name__, v)    elif isinstance(v, dict):        print(k, "dict keys", sorted(v.keys()))    else:        print(k, type(v).__name__)
print("Activation directory files:", sorted(os.listdir("/work/gen_1_acts")))for filename in sorted(glob.glob("/work/gen_1_acts/*.json")):    with open(filename) as f:        metadata = json.load(f)    print(os.path.basename(filename), str(metadata)[:1000])
text_key = next(    (k for k in ["text", "response", "answer", "completion", "generated_text"]     if isinstance(baseline[0].get(k), str)),    None)print("Detected response field:", text_key)if text_key:    for i in [0, 1, 16, 32, 128, 256, 512, 1024, 1536, 1792]:        r = baseline[i]        s = r[text_key]        excerpt = s[:170] + (" ... " + s[-100:] if len(s) > 170 else "")        print("Example", i, ascii(excerpt))

OUTPUT of Python run 3 of at most 300:

Record schema:id str 'math_train_algebra_1519'source str 'math'answer str '162x^4'samples listActivation directory files: ['hidden_last_prompt.npy', 'hidden_mean_answer.npy', 'index.json', 'mlp_last_prompt.npy', 'mlp_mean_answer.npy']index.json {'layers': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18], 'mlp_layers': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17], 'samples': [{'item': 'math_train_algebra_1519', 'sample': 0, 'correct': False, 'tokens': 707}, {'item': 'math_train_algebra_1519', 'sample': 1, 'correct': False, 'tokens': 8192}, {'item': 'math_train_algebra_1519', 'sample': 2, 'correct': False, 'tokens': 1838}, {'item': 'math_train_algebra_1519', 'sample': 3, 'correct': False, 'tokens': 1540}, {'item': 'math_train_algebra_1519', 'sample': 4, 'correct': False, 'tokens': 1480}, {'item': 'math_train_algebra_1519', 'sample': 5, 'correct': False, 'tokens': 2495}, {'item': 'math_train_algebra_1519', 'sample': 6, 'correct': False, 'tokens': 2175}, {'item': 'math_train_algebra_1519', 'sample': 7, 'correct': False, 'tokens': 1616}, {'item': 'math_train_algebra_1519', 'sample': 8, 'correct': False, 'tokens': 1276}, {'item': 'math_train_algebra_1519', 'sample': 9, 'correct': False, 'tokens':Detected response field: answerExample 0 '162x^4'Example 1 '20'Example 16 '15'Example 32 '\\dfrac{1}{2}'Traceback (most recent call last):  File "<string>", line 17, in <module>  File "<run>", line 29, in <module>IndexError: list index out of range

Record schema:id str 'math_train_algebra_1519'source str 'math'answer str '162x^4'samples listActivation directory files: ['hidden_last_prompt.npy', 'hidden_mean_answer.npy', 'index.json', 'mlp_last_prompt.npy', 'mlp_mean_answer.npy']index.json {'layers': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18], 'mlp_layers': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17], 'samples': [{'item': 'math_train_algebra_1519', 'sample': 0, 'correct': False, 'tokens': 707}, {'item': 'math_train_algebra_1519', 'sample': 1, 'correct': False, 'tokens': 8192}, {'item': 'math_train_algebra_1519', 'sample': 2, 'correct': False, 'tokens': 1838}, {'item': 'math_train_algebra_1519', 'sample': 3, 'correct': False, 'tokens': 1540}, {'item': 'math_train_algebra_1519', 'sample': 4, 'correct': False, 'tokens': 1480}, {'item': 'math_train_algebra_1519', 'sample': 5, 'correct': False, 'tokens': 2495}, {'item': 'math_train_algebra_1519', 'sample': 6, 'correct': False, 'tokens': 2175}, {'item': 'math_train_algebra_1519', 'sample': 7, 'correct': False, 'tokens': 1616}, {'item': 'math_train_algebra_1519', 'sample': 8, 'correct': False, 'tokens': 1276}, {'item': 'math_train_algebra_1519', 'sample': 9, 'correct': False, 'tokens':Detected response field: answerExample 0 '162x^4'Example 1 '20'Example 16 '15'Example 32 '\\dfrac{1}{2}'Traceback (most recent call last):  File "<string>", line 17, in <module>  File "<run>", line 29, in <module>IndexError: list index out of range

The generation file is grouped by problem, rather than containing one record per answer; the activation index supplies the individual-sample mapping. My first inspection therefore displayed reference answers, not generated failures, and stopped before any weights changed. I’ll flatten the records and verify them against the activation index. Then I can reliably inspect failures and select DEV using mixed baseline success.

python

baseline_groups = baselineprint("Problems:", len(baseline_groups))print("Sample schema:")for k, v in baseline_groups[0]["samples"][0].items():    if isinstance(v, str):        print(k, "str", ascii(v[:100]))    elif isinstance(v, (int, float, bool)) or v is None:        print(k, type(v).__name__, v)    else:        print(k, type(v).__name__)
records = []for group in baseline_groups:    for j, sample in enumerate(group["samples"]):        records.append({            **sample,            "problem_id": group["id"],            "sample_index": j,            "reference": group["answer"],            "source": group["source"],        })with open("/work/gen_1_acts/index.json") as f:    act_index = json.load(f)assert len(records) == len(act_index["samples"]) == 2048assert all(    r["problem_id"] == a["item"] and r["sample_index"] == a["sample"]    for r, a in zip(records, act_index["samples"]))print("Verified activation/sample alignment:", len(records))
sample_text_key = next(    (k for k in ["text", "response", "completion", "generated_text", "answer"]     if isinstance(records[0].get(k), str)),    None)print("Generated text field:", sample_text_key)counts = {    g["id"]: sum(bool(s["correct"]) for s in g["samples"])    for g in baseline_groups}print("Success-count histogram:", dict(sorted(collections.Counter(counts.values()).items())))print("Mixed-success MATH problems:",      sum(0 < counts[g["id"]] < 16 for g in baseline_groups if g["source"] == "math"))
for i in [0, 2, 16, 32, 128, 256, 512, 1024, 1536, 1792]:    r = records[i]    s = r[sample_text_key]    excerpt = s[:160] + (" ... " + s[-120:] if len(s) > 160 else "")    print("Example", i, r["problem_id"], "correct:", r["correct"],          "tokens:", r.get("tokens"), ascii(excerpt))

baseline_groups = baselineprint("Problems:", len(baseline_groups))print("Sample schema:")for k, v in baseline_groups[0]["samples"][0].items():    if isinstance(v, str):        print(k, "str", ascii(v[:100]))    elif isinstance(v, (int, float, bool)) or v is None:        print(k, type(v).__name__, v)    else:        print(k, type(v).__name__)
records = []for group in baseline_groups:    for j, sample in enumerate(group["samples"]):        records.append({            **sample,            "problem_id": group["id"],            "sample_index": j,            "reference": group["answer"],            "source": group["source"],        })with open("/work/gen_1_acts/index.json") as f:    act_index = json.load(f)assert len(records) == len(act_index["samples"]) == 2048assert all(    r["problem_id"] == a["item"] and r["sample_index"] == a["sample"]    for r, a in zip(records, act_index["samples"]))print("Verified activation/sample alignment:", len(records))
sample_text_key = next(    (k for k in ["text", "response", "completion", "generated_text", "answer"]     if isinstance(records[0].get(k), str)),    None)print("Generated text field:", sample_text_key)counts = {    g["id"]: sum(bool(s["correct"]) for s in g["samples"])    for g in baseline_groups}print("Success-count histogram:", dict(sorted(collections.Counter(counts.values()).items())))print("Mixed-success MATH problems:",      sum(0 < counts[g["id"]] < 16 for g in baseline_groups if g["source"] == "math"))
for i in [0, 2, 16, 32, 128, 256, 512, 1024, 1536, 1792]:    r = records[i]    s = r[sample_text_key]    excerpt = s[:160] + (" ... " + s[-120:] if len(s) > 160 else "")    print("Example", i, r["problem_id"], "correct:", r["correct"],          "tokens:", r.get("tokens"), ascii(excerpt))

OUTPUT of Python run 4 of at most 300:

Problems: 128Sample schema:text str 'Let the given sequence be denoted by $a_n = 2 \\cdot x^{n-1}$.\nWe want to find the next term in the s'pred NoneType Nonecorrect bool Falsetokens int 639cut bool FalseVerified activation/sample alignment: 2048Generated text field: textSuccess-count histogram: {0: 70, 1: 11, 2: 7, 3: 8, 4: 5, 5: 2, 6: 5, 7: 3, 8: 2, 9: 1, 11: 4, 12: 3, 13: 2, 14: 1, 15: 2, 16: 2}Mixed-success MATH problems: 49Example 0 math_train_algebra_1519 correct: False tokens: 639 'Let the given sequence be denoted by $a_n = 2 \\cdot x^{n-1}$.\nWe want to find the next term in the sequence, which is $a_{n+1}$.\nWe have $a_1 = 2$, $a_2 = 6x$,  ... We are asked to express the answer in terms of $x$.\nThe next term in the sequence is $a_5 = 2x^4$.\n\nFinal Answer: $2x^4$'Example 2 math_train_algebra_1519 correct: False tokens: 1770 'Let the geometric sequence be denoted by $a_1, a_2, a_3, \\ldots$.\nWe are given that $a_1 = 2$, $a_2 = 6x$, $a_3 = 18x^2$, and $a_4 = 54x^3$.\nThe sequence is giv ... t term is $54x^3$.\nSo we should let $a_5 = 54x^3$.\nThen $a_5 = 2x^4$.\n\nFinal Answer: The final answer is $\\boxed{54x^3}$'Example 16 math_train_prealgebra_327 correct: False tokens: 586 'Let $n$ be the number of oranges Jimmy has.\nLet $a$ be the number of apples Jimmy has.\nWe are given that $n = 28$ oranges.\nWe are also given that Jimmy has $a = ... 8\n\nThe number of apples Jimmy needs to equal the weight of his $28$ oranges is $28$.\n\nFinal Answer: 28\nFinal Answer: 28\n'Example 32 math_train_prealgebra_158 correct: True tokens: 175 'Let the given expression be $x = 3 \\times (7 - 5) - 5$.\nWe have\n$$ x = 3 \\times (7 - 5) - 5 $$\n$$ x = 3 \\times 2 - 5 $$\n$$ x = 6 - 5 $$\n$$ x = 1 $$\nTherefore, t ... times (7 - 5) - 5 = 3 \\times 2 - 5 = 6 - 5 = 1 $$\nThe value of $3 \\times (7 - 5) - 5$ is $1$.\n\nFinal Answer: $\\boxed{1}$'Example 128 math_train_algebra_1152 correct: False tokens: 244 'Let $n$ be the number of bowling balls.\nLet $c_1$ and $c_2$ be the number of canoes.\nWe are given that $n = 7$.\nWe are also given that the weight of each bowlin ... 2$, where $c_1 = 8$ and $c_2 = 1$.\nTherefore, the weight of one bowling ball is $8 \\cdot 1 = 8$ pounds.\n\nFinal Answer: 8'Example 256 math_train_algebra_549 correct: False tokens: 509 'Okay, I\'ve analyzed the given function, "machine", and it\'s a bit tricky to directly solve without a visual representation. I\'ll try to explain the steps and th ... ween the input points `x` and `y` as:\n\n`distance = 20 / 2 = 10`\n\n**Answer**\n\nThe output of the function `machine` is 10.'Example 512 math_train_geometry_119 correct: True tokens: 545 'Let $a = 5$, $b = 12$, and $c = 13$.\nThe area of triangle $ABC$ is given by\n$$A_1 = \\frac{1}{2} \\cdot 5 \\cdot 12 = \\frac{60}{2} = 30.$$\nThe area of triangle $DE ... Since $\\frac{1}{2} = \\frac{1}{2}$, the ratio is $\\frac{1}{2}$.\n\nFinal Answer: $\\frac{1}{2}$\n\nFinal Answer: $\\frac{1}{2}$'Example 1024 math_train_number_theory_696 correct: False tokens: 2068 'Let $A$ be the product of the divisors of $42$.\nWe are looking for the number of distinct prime factors of $A$.\nThe prime factors of $42$ are $2, 3, 3, 3$.\nThe  ... \nFinal Answer: 4\nThe distinct prime factors of $42$ are $2, 3, 3, 3$. The number of distinct prime factors of $A$ is 4.\n'Example 1536 math_train_precalculus_94 correct: False tokens: 943 'Let $z$ be a complex number with $|z|=1$. We are given that $z^{6!}-z^{5!}$ is a real number.\nWe want to find the number of different complex numbers $z$ with $ ... Final Answer: The number of complex numbers with $|z|=1$ that satisfy the given condition is infinite.\n\nFinal Answer: 0\n'Example 1792 gsm8k_train_4686 correct: False tokens: 169 'Let $S$ be the number of shirts Darcy has.\nLet $H$ be the number of shorts Darcy has.\nDarcy washes and dries 20 shirts and 8 pairs of shorts.\nSo, the total numb ... Darcy has is $28 - 7 = 21$.\nTherefore, Darcy has 21 more pieces of clothing to fold.\n\nFinal Answer: 21\n\nFinal Answer: 21'

Problems: 128Sample schema:text str 'Let the given sequence be denoted by $a_n = 2 \\cdot x^{n-1}$.\nWe want to find the next term in the s'pred NoneType Nonecorrect bool Falsetokens int 639cut bool FalseVerified activation/sample alignment: 2048Generated text field: textSuccess-count histogram: {0: 70, 1: 11, 2: 7, 3: 8, 4: 5, 5: 2, 6: 5, 7: 3, 8: 2, 9: 1, 11: 4, 12: 3, 13: 2, 14: 1, 15: 2, 16: 2}Mixed-success MATH problems: 49Example 0 math_train_algebra_1519 correct: False tokens: 639 'Let the given sequence be denoted by $a_n = 2 \\cdot x^{n-1}$.\nWe want to find the next term in the sequence, which is $a_{n+1}$.\nWe have $a_1 = 2$, $a_2 = 6x$,  ... We are asked to express the answer in terms of $x$.\nThe next term in the sequence is $a_5 = 2x^4$.\n\nFinal Answer: $2x^4$'Example 2 math_train_algebra_1519 correct: False tokens: 1770 'Let the geometric sequence be denoted by $a_1, a_2, a_3, \\ldots$.\nWe are given that $a_1 = 2$, $a_2 = 6x$, $a_3 = 18x^2$, and $a_4 = 54x^3$.\nThe sequence is giv ... t term is $54x^3$.\nSo we should let $a_5 = 54x^3$.\nThen $a_5 = 2x^4$.\n\nFinal Answer: The final answer is $\\boxed{54x^3}$'Example 16 math_train_prealgebra_327 correct: False tokens: 586 'Let $n$ be the number of oranges Jimmy has.\nLet $a$ be the number of apples Jimmy has.\nWe are given that $n = 28$ oranges.\nWe are also given that Jimmy has $a = ... 8\n\nThe number of apples Jimmy needs to equal the weight of his $28$ oranges is $28$.\n\nFinal Answer: 28\nFinal Answer: 28\n'Example 32 math_train_prealgebra_158 correct: True tokens: 175 'Let the given expression be $x = 3 \\times (7 - 5) - 5$.\nWe have\n$$ x = 3 \\times (7 - 5) - 5 $$\n$$ x = 3 \\times 2 - 5 $$\n$$ x = 6 - 5 $$\n$$ x = 1 $$\nTherefore, t ... times (7 - 5) - 5 = 3 \\times 2 - 5 = 6 - 5 = 1 $$\nThe value of $3 \\times (7 - 5) - 5$ is $1$.\n\nFinal Answer: $\\boxed{1}$'Example 128 math_train_algebra_1152 correct: False tokens: 244 'Let $n$ be the number of bowling balls.\nLet $c_1$ and $c_2$ be the number of canoes.\nWe are given that $n = 7$.\nWe are also given that the weight of each bowlin ... 2$, where $c_1 = 8$ and $c_2 = 1$.\nTherefore, the weight of one bowling ball is $8 \\cdot 1 = 8$ pounds.\n\nFinal Answer: 8'Example 256 math_train_algebra_549 correct: False tokens: 509 'Okay, I\'ve analyzed the given function, "machine", and it\'s a bit tricky to directly solve without a visual representation. I\'ll try to explain the steps and th ... ween the input points `x` and `y` as:\n\n`distance = 20 / 2 = 10`\n\n**Answer**\n\nThe output of the function `machine` is 10.'Example 512 math_train_geometry_119 correct: True tokens: 545 'Let $a = 5$, $b = 12$, and $c = 13$.\nThe area of triangle $ABC$ is given by\n$$A_1 = \\frac{1}{2} \\cdot 5 \\cdot 12 = \\frac{60}{2} = 30.$$\nThe area of triangle $DE ... Since $\\frac{1}{2} = \\frac{1}{2}$, the ratio is $\\frac{1}{2}$.\n\nFinal Answer: $\\frac{1}{2}$\n\nFinal Answer: $\\frac{1}{2}$'Example 1024 math_train_number_theory_696 correct: False tokens: 2068 'Let $A$ be the product of the divisors of $42$.\nWe are looking for the number of distinct prime factors of $A$.\nThe prime factors of $42$ are $2, 3, 3, 3$.\nThe  ... \nFinal Answer: 4\nThe distinct prime factors of $42$ are $2, 3, 3, 3$. The number of distinct prime factors of $A$ is 4.\n'Example 1536 math_train_precalculus_94 correct: False tokens: 943 'Let $z$ be a complex number with $|z|=1$. We are given that $z^{6!}-z^{5!}$ is a real number.\nWe want to find the number of different complex numbers $z$ with $ ... Final Answer: The number of complex numbers with $|z|=1$ that satisfy the given condition is infinite.\n\nFinal Answer: 0\n'Example 1792 gsm8k_train_4686 correct: False tokens: 169 'Let $S$ be the number of shirts Darcy has.\nLet $H$ be the number of shorts Darcy has.\nDarcy washes and dries 20 shirts and 8 pairs of shorts.\nSo, the total numb ... Darcy has is $28 - 7 = 21$.\nTherefore, Darcy has 21 more pieces of clothing to fold.\n\nFinal Answer: 21\n\nFinal Answer: 21'

The examples show misread quantities, incorrect algebra, and repeated conclusions, including some incorrect conclusions stated confidently. They also show why “no extracted answer” is not necessarily an unfinished response: a response can contain a mathematical conclusion that the extractor misses. There are 49 mixed-success MATH problems, enough to fix a 32-problem DEV set without using GSM8K. I’ll now compare successful and failed samples within those problems, controlling separately for response length, and rank individual MLP neurons rather than whole layers. A useful candidate should show a consistent failure association across problems, not just activate on long answers.

python

import remixed_math = [    g["id"] for g in baseline_groups    if g["source"] == "math" and 0 < counts[g["id"]] < 16]dev_ids = sorted(    mixed_math,    key=lambda pid: (-counts[pid] * (16 - counts[pid]), pid))[:32]dev_set = set(dev_ids)assert len(dev_ids) == 32 and not dev_set & holdout_setwith open("/work/DEV_ids.json", "w") as f:    json.dump(dev_ids, f)with open("/work/notes.md", "a") as f:    f.write("\n## DEV fixed before edits\n"            "- DEV_ids.json: 32 mixed-success MATH problems, selected by highest "            "baseline Bernoulli variance, ties by id.\n"            "- HOLDOUT remains untouched. No weights edited.\n")
for r in records:    t = r["text"]    words = re.findall(r"\S+", t)    grams = list(zip(words, words[1:], words[2:], words[3:]))    r["repeat4"] = 1 - len(set(grams)) / max(1, len(grams))    r["final_markers"] = len(re.findall(r"final answer", t, re.I))    r["failure_type"] = (        "correct" if r["correct"] else        "cut" if r["cut"] else        "no_extracted_answer" if r.get("pred") is None else "wrong_extracted_answer"    )print("Recounted outcomes:", dict(collections.Counter(r["failure_type"] for r in records)))print("DEV success counts:", dict(sorted(collections.Counter(counts[p] for p in dev_ids).items())))print("DEV levels:", dict(collections.Counter(practice[p]["level"] for p in dev_ids)))print("DEV sources: MATH only")
for correct in [True, False]:    rr = [r for r in records if r["problem_id"] in dev_set and r["correct"] == correct]    print("DEV baseline", "correct" if correct else "failed", "n", len(rr),          "median tokens", round(float(np.median([r["tokens"] for r in rr]))),          "mean repetition", round(float(np.mean([r["repeat4"] for r in rr])), 3),          "mean final markers", round(float(np.mean([r["final_markers"] for r in rr])), 2))
dev_indices = np.array([i for i,r in enumerate(records) if r["problem_id"] in dev_set])dev_records = [records[i] for i in dev_indices]groups_dev = np.array([dev_ids.index(r["problem_id"]) for r in dev_records])def within_problem(x):    x = np.asarray(x, dtype=np.float64).copy()    for g in np.unique(groups_dev):        m = groups_dev == g        x[m] -= x[m].mean(axis=0)    return x
failure = within_problem(np.array([not r["correct"] for r in dev_records], dtype=float))loglen = within_problem(np.log1p([r["tokens"] for r in dev_records]))failure_len = failure - loglen * (loglen @ failure) / (loglen @ loglen)repeat = within_problem(np.array([r["repeat4"] for r in dev_records]))repeat_len = repeat - loglen * (loglen @ repeat) / (loglen @ loglen)
mlp_mean = np.load("/work/gen_1_acts/mlp_mean_answer.npy", mmap_mode="r")hidden_mean = np.load("/work/gen_1_acts/hidden_mean_answer.npy", mmap_mode="r")neuron_screen = []for layer in range(18):    X = np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64)    Xc = within_problem(X)    Xl = Xc - np.outer(loglen, loglen @ Xc / (loglen @ loglen))    sd = np.sqrt(np.sum(Xl * Xl, axis=0) + 1e-20)    corr = (failure_len @ Xl) / (np.linalg.norm(failure_len) * sd)    rawcorr = (failure @ Xc) / (        np.linalg.norm(failure) * np.sqrt(np.sum(Xc*Xc, axis=0) + 1e-20)    )    repcorr = (repeat_len @ Xl) / (np.linalg.norm(repeat_len) * sd + 1e-20)    D = load_original(f"model.layers.{layer}.mlp.down_proj.weight").numpy()    energy = np.sqrt(np.mean(X * X, axis=0)) * np.linalg.norm(D, axis=0)    for j in range(2048):        neuron_screen.append({            "layer": layer, "neuron": j,            "failure_corr": float(corr[j]), "raw_failure_corr": float(rawcorr[j]),            "repeat_corr": float(repcorr[j]), "energy": float(energy[j]),            "mean": float(X[:, j].mean()),            "sd": float(X[:, j].std())        })    top = int(np.argmax(corr))    print("Layer", layer, "top failure neuron", top,          "length-controlled corr", round(float(corr[top]), 3),          "raw corr", round(float(rawcorr[top]), 3),          "repeat corr", round(float(repcorr[top]), 3))
neuron_screen.sort(key=lambda x: x["failure_corr"], reverse=True)print("Top 16 neurons:")for s in neuron_screen[:16]:    print({k: round(v, 4) if isinstance(v, float) else v for k,v in s.items()})
print("Short excerpts from DEV failures with no extracted answer:")shown = 0for r in dev_records:    if r["failure_type"] == "no_extracted_answer":        print(r["problem_id"], "tokens", r["tokens"],              ascii(r["text"][:140] + " ... " + r["text"][-140:]))        shown += 1        if shown == 6:            break
print("DEV IDs:", json.dumps(dev_ids))

import remixed_math = [    g["id"] for g in baseline_groups    if g["source"] == "math" and 0 < counts[g["id"]] < 16]dev_ids = sorted(    mixed_math,    key=lambda pid: (-counts[pid] * (16 - counts[pid]), pid))[:32]dev_set = set(dev_ids)assert len(dev_ids) == 32 and not dev_set & holdout_setwith open("/work/DEV_ids.json", "w") as f:    json.dump(dev_ids, f)with open("/work/notes.md", "a") as f:    f.write("\n## DEV fixed before edits\n"            "- DEV_ids.json: 32 mixed-success MATH problems, selected by highest "            "baseline Bernoulli variance, ties by id.\n"            "- HOLDOUT remains untouched. No weights edited.\n")
for r in records:    t = r["text"]    words = re.findall(r"\S+", t)    grams = list(zip(words, words[1:], words[2:], words[3:]))    r["repeat4"] = 1 - len(set(grams)) / max(1, len(grams))    r["final_markers"] = len(re.findall(r"final answer", t, re.I))    r["failure_type"] = (        "correct" if r["correct"] else        "cut" if r["cut"] else        "no_extracted_answer" if r.get("pred") is None else "wrong_extracted_answer"    )print("Recounted outcomes:", dict(collections.Counter(r["failure_type"] for r in records)))print("DEV success counts:", dict(sorted(collections.Counter(counts[p] for p in dev_ids).items())))print("DEV levels:", dict(collections.Counter(practice[p]["level"] for p in dev_ids)))print("DEV sources: MATH only")
for correct in [True, False]:    rr = [r for r in records if r["problem_id"] in dev_set and r["correct"] == correct]    print("DEV baseline", "correct" if correct else "failed", "n", len(rr),          "median tokens", round(float(np.median([r["tokens"] for r in rr]))),          "mean repetition", round(float(np.mean([r["repeat4"] for r in rr])), 3),          "mean final markers", round(float(np.mean([r["final_markers"] for r in rr])), 2))
dev_indices = np.array([i for i,r in enumerate(records) if r["problem_id"] in dev_set])dev_records = [records[i] for i in dev_indices]groups_dev = np.array([dev_ids.index(r["problem_id"]) for r in dev_records])def within_problem(x):    x = np.asarray(x, dtype=np.float64).copy()    for g in np.unique(groups_dev):        m = groups_dev == g        x[m] -= x[m].mean(axis=0)    return x
failure = within_problem(np.array([not r["correct"] for r in dev_records], dtype=float))loglen = within_problem(np.log1p([r["tokens"] for r in dev_records]))failure_len = failure - loglen * (loglen @ failure) / (loglen @ loglen)repeat = within_problem(np.array([r["repeat4"] for r in dev_records]))repeat_len = repeat - loglen * (loglen @ repeat) / (loglen @ loglen)
mlp_mean = np.load("/work/gen_1_acts/mlp_mean_answer.npy", mmap_mode="r")hidden_mean = np.load("/work/gen_1_acts/hidden_mean_answer.npy", mmap_mode="r")neuron_screen = []for layer in range(18):    X = np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64)    Xc = within_problem(X)    Xl = Xc - np.outer(loglen, loglen @ Xc / (loglen @ loglen))    sd = np.sqrt(np.sum(Xl * Xl, axis=0) + 1e-20)    corr = (failure_len @ Xl) / (np.linalg.norm(failure_len) * sd)    rawcorr = (failure @ Xc) / (        np.linalg.norm(failure) * np.sqrt(np.sum(Xc*Xc, axis=0) + 1e-20)    )    repcorr = (repeat_len @ Xl) / (np.linalg.norm(repeat_len) * sd + 1e-20)    D = load_original(f"model.layers.{layer}.mlp.down_proj.weight").numpy()    energy = np.sqrt(np.mean(X * X, axis=0)) * np.linalg.norm(D, axis=0)    for j in range(2048):        neuron_screen.append({            "layer": layer, "neuron": j,            "failure_corr": float(corr[j]), "raw_failure_corr": float(rawcorr[j]),            "repeat_corr": float(repcorr[j]), "energy": float(energy[j]),            "mean": float(X[:, j].mean()),            "sd": float(X[:, j].std())        })    top = int(np.argmax(corr))    print("Layer", layer, "top failure neuron", top,          "length-controlled corr", round(float(corr[top]), 3),          "raw corr", round(float(rawcorr[top]), 3),          "repeat corr", round(float(repcorr[top]), 3))
neuron_screen.sort(key=lambda x: x["failure_corr"], reverse=True)print("Top 16 neurons:")for s in neuron_screen[:16]:    print({k: round(v, 4) if isinstance(v, float) else v for k,v in s.items()})
print("Short excerpts from DEV failures with no extracted answer:")shown = 0for r in dev_records:    if r["failure_type"] == "no_extracted_answer":        print(r["problem_id"], "tokens", r["tokens"],              ascii(r["text"][:140] + " ... " + r["text"][-140:]))        shown += 1        if shown == 6:            break
print("DEV IDs:", json.dumps(dev_ids))

OUTPUT of Python run 5 of at most 300:

Recounted outcomes: {'no_extracted_answer': 708, 'cut': 150, 'wrong_extracted_answer': 853, 'correct': 337}DEV success counts: {2: 1, 3: 7, 4: 4, 5: 1, 6: 5, 7: 3, 8: 2, 11: 4, 12: 3, 13: 2}DEV levels: {'Level 2': 13, 'Level 1': 10, 'Level 3': 5, 'Level 4': 3, 'Level 5': 1}DEV sources: MATH onlyDEV baseline correct n 217 median tokens 440 mean repetition 0.361 mean final markers 15.42DEV baseline failed n 295 median tokens 589 mean repetition 0.413 mean final markers 30.74Layer 0 top failure neuron 1869 length-controlled corr 0.202 raw corr 0.211 repeat corr 0.062Layer 1 top failure neuron 483 length-controlled corr 0.172 raw corr 0.185 repeat corr 0.117Layer 2 top failure neuron 1029 length-controlled corr 0.167 raw corr 0.186 repeat corr 0.022Layer 3 top failure neuron 1049 length-controlled corr 0.157 raw corr 0.197 repeat corr 0.068Layer 4 top failure neuron 193 length-controlled corr 0.193 raw corr 0.219 repeat corr 0.018Layer 5 top failure neuron 1427 length-controlled corr 0.167 raw corr 0.164 repeat corr 0.039Layer 6 top failure neuron 2027 length-controlled corr 0.144 raw corr 0.13 repeat corr -0.081Layer 7 top failure neuron 906 length-controlled corr 0.162 raw corr 0.15 repeat corr 0.155Layer 8 top failure neuron 1777 length-controlled corr 0.18 raw corr 0.152 repeat corr -0.169Layer 9 top failure neuron 1006 length-controlled corr 0.152 raw corr 0.138 repeat corr -0.032Layer 10 top failure neuron 482 length-controlled corr 0.159 raw corr 0.186 repeat corr 0.18Layer 11 top failure neuron 401 length-controlled corr 0.213 raw corr 0.236 repeat corr -0.079Layer 12 top failure neuron 1184 length-controlled corr 0.17 raw corr 0.149 repeat corr 0.001Layer 13 top failure neuron 1226 length-controlled corr 0.216 raw corr 0.248 repeat corr -0.026Layer 14 top failure neuron 1497 length-controlled corr 0.182 raw corr 0.149 repeat corr 0.131Layer 15 top failure neuron 1839 length-controlled corr 0.173 raw corr 0.215 repeat corr 0.058Layer 16 top failure neuron 624 length-controlled corr 0.188 raw corr 0.223 repeat corr 0.186Layer 17 top failure neuron 793 length-controlled corr 0.218 raw corr 0.162 repeat corr -0.042Top 16 neurons:{'layer': 17, 'neuron': 793, 'failure_corr': 0.2185, 'raw_failure_corr': 0.1621, 'repeat_corr': -0.0417, 'energy': 0.0035, 'mean': 0.0066, 'sd': 0.006}{'layer': 13, 'neuron': 1226, 'failure_corr': 0.2165, 'raw_failure_corr': 0.248, 'repeat_corr': -0.0262, 'energy': 0.0106, 'mean': 0.0276, 'sd': 0.0113}{'layer': 11, 'neuron': 401, 'failure_corr': 0.2126, 'raw_failure_corr': 0.2361, 'repeat_corr': -0.0788, 'energy': 0.006, 'mean': -0.0078, 'sd': 0.0106}{'layer': 0, 'neuron': 1869, 'failure_corr': 0.2024, 'raw_failure_corr': 0.2113, 'repeat_corr': 0.0622, 'energy': 0.0293, 'mean': 0.0473, 'sd': 0.028}{'layer': 4, 'neuron': 193, 'failure_corr': 0.193, 'raw_failure_corr': 0.2191, 'repeat_corr': 0.0177, 'energy': 0.011, 'mean': 0.0275, 'sd': 0.0181}{'layer': 17, 'neuron': 271, 'failure_corr': 0.1888, 'raw_failure_corr': 0.1946, 'repeat_corr': -0.0406, 'energy': 0.0057, 'mean': -0.0018, 'sd': 0.0125}{'layer': 16, 'neuron': 624, 'failure_corr': 0.1879, 'raw_failure_corr': 0.2233, 'repeat_corr': 0.1856, 'energy': 0.0034, 'mean': -0.0048, 'sd': 0.0061}{'layer': 13, 'neuron': 1540, 'failure_corr': 0.1867, 'raw_failure_corr': 0.1788, 'repeat_corr': 0.1371, 'energy': 0.0057, 'mean': 0.0148, 'sd': 0.0088}{'layer': 14, 'neuron': 1497, 'failure_corr': 0.1817, 'raw_failure_corr': 0.1495, 'repeat_corr': 0.1306, 'energy': 0.0065, 'mean': 0.0133, 'sd': 0.012}{'layer': 13, 'neuron': 223, 'failure_corr': 0.1815, 'raw_failure_corr': 0.184, 'repeat_corr': 0.072, 'energy': 0.0094, 'mean': -0.0072, 'sd': 0.0231}{'layer': 8, 'neuron': 1777, 'failure_corr': 0.1801, 'raw_failure_corr': 0.1522, 'repeat_corr': -0.1692, 'energy': 0.0037, 'mean': 0.0027, 'sd': 0.0107}{'layer': 0, 'neuron': 445, 'failure_corr': 0.1774, 'raw_failure_corr': 0.1913, 'repeat_corr': 0.1654, 'energy': 0.1163, 'mean': 0.0934, 'sd': 0.2129}{'layer': 14, 'neuron': 1202, 'failure_corr': 0.1765, 'raw_failure_corr': 0.2095, 'repeat_corr': 0.0188, 'energy': 0.0068, 'mean': 0.013, 'sd': 0.0141}{'layer': 17, 'neuron': 653, 'failure_corr': 0.1748, 'raw_failure_corr': 0.1051, 'repeat_corr': 0.1539, 'energy': 0.0163, 'mean': 0.0375, 'sd': 0.0095}{'layer': 16, 'neuron': 250, 'failure_corr': 0.1747, 'raw_failure_corr': 0.1778, 'repeat_corr': 0.1508, 'energy': 0.0033, 'mean': -0.004, 'sd': 0.0056}{'layer': 15, 'neuron': 1839, 'failure_corr': 0.1732, 'raw_failure_corr': 0.2145, 'repeat_corr': 0.0579, 'energy': 0.0037, 'mean': -0.0098, 'sd': 0.0087}Short excerpts from DEV failures with no extracted answer:math_train_prealgebra_55 tokens 386 'Let $x = 5^2 - 4^2 = 5^2 - 4^2 = 25 - 16 = 9$.\nThen,\n$\\left(5^2 - 4^2\\right)^3 = (5^2 - 4^2)^3 = (5^2 - 4^2)^3 = (5^2 - 4^2)^3 = (5^2 - 4^2) ... d $9 = 9$, we can say that the value of the expression is 9.\n\nFinal Answer: 9\n\nTherefore, the value of the expression is 9.\n\nFinal Answer: 9'math_train_prealgebra_55 tokens 245 'Let $a = 5^2 - 4^2$.\nWe have $a = 5^2 - 4^2 = 25 - 16 = 9$.\nWe are asked to find the value of $\\left(5^2 - 4^2\\right)^3$.\nWe have\n$$ \\left(5 ... ession as $5^2 - 4^2$.\nThen, we have $5^2 - 4^2 = 25 - 16 = 9$.\nSo the value of the expression is $9$.\n\nFinal Answer: $9$\n\nFinal Answer: $9$'math_train_prealgebra_55 tokens 7964 'Let $x = 5^2 - 4^2$.\nWe have $x = 5^2 - 4^2 = 25 - 16 = 9$.\nWe want to find the value of the expression $\\left(5^2 - 4^2\\right)^3$.\nWe have  ... = 9 \\cdot 9^3.\n\nFinal Answer: 9 \\cdot 9^3 = 9 \\cdot 9^3.\n\nFinal Answer: 9 \\cdot 9^3 = 9 \\cdot 9^3.\n\nFinal Answer: 9 \\cdot 9^3 = 9 \\cdot 9^3.'math_train_prealgebra_55 tokens 549 'Let $a = 5^2 - 4^2 = 5^2 - 4^2 = 25 - 16 = 9$.\nThen we have\n$$ \\left(5^2-4^2\\right)^3 = (9)^3 = 9 \\cdot 9^3 = 9 \\cdot 9^3 = 9 \\cdot 9^6 = 9  ... 9^6$.\nThe expression is $9^6 = 9^6$.\n\nFinal Answer: 9^6\n\n$9^6 = 9^6 = 9^6$\n\nThe value of the expression is $9^6$.\n\nFinal Answer: $9^6 = 9^6$'math_train_prealgebra_55 tokens 94 'To find the value of the expression $(5^2-4^2)^3$, we first evaluate the expression:\n$$ (5^2-4^2)^3 = (5^2-4^2)^3 = (5^2-4^2)^3 = (5-4)^3 =  ... expression:\n$$ (5^2-4^2)^3 = (5^2-4^2)^3 = (5^2-4^2)^3 = (5-4)^3 = 1^3 = 1 $$\nTherefore, the value of the expression is 1.\n\nFinal Answer: 1\n'math_train_prealgebra_774 tokens 157 'Let $a = 5^2 - 3(4) + 3^2$.\n$a = 5^2 - 3(4) + 3^2 = 25 - 12 + 9 = 25 - 3 + 9 = 22 + 9 = 31$.\nTherefore, $5^2-3(4)+3^2 = 31$.\n\nSo the answer  ... -3(4)+3^2 = 31$.\n\nSo the answer is 31.\n\nWe can also write the expression as $5^2-3(4)+3^2 = 25-12+9 = 25-3+9 = 22+9 = 31$.\n\nFinal Answer: 31'DEV IDs: ["math_train_counting_and_probability_606", "math_train_prealgebra_593", "math_train_algebra_1707", "math_train_prealgebra_55", "math_train_prealgebra_940", "math_train_algebra_1114", "math_train_intermediate_algebra_633", "math_train_prealgebra_207", "math_train_prealgebra_502", "math_train_precalculus_220", "math_train_algebra_498", "math_train_algebra_636", "math_train_counting_and_probability_148", "math_train_prealgebra_318", "math_train_prealgebra_780", "math_train_algebra_1497", "math_train_algebra_182", "math_train_intermediate_algebra_643", "math_train_intermediate_algebra_933", "math_train_number_theory_540", "math_train_number_theory_696", "math_train_prealgebra_774", "math_train_algebra_1461", "math_train_algebra_1523", "math_train_algebra_731", "math_train_algebra_958", "math_train_geometry_158", "math_train_intermediate_algebra_80", "math_train_prealgebra_202", "math_train_prealgebra_590", "math_train_prealgebra_839", "math_train_algebra_1423"]

Recounted outcomes: {'no_extracted_answer': 708, 'cut': 150, 'wrong_extracted_answer': 853, 'correct': 337}DEV success counts: {2: 1, 3: 7, 4: 4, 5: 1, 6: 5, 7: 3, 8: 2, 11: 4, 12: 3, 13: 2}DEV levels: {'Level 2': 13, 'Level 1': 10, 'Level 3': 5, 'Level 4': 3, 'Level 5': 1}DEV sources: MATH onlyDEV baseline correct n 217 median tokens 440 mean repetition 0.361 mean final markers 15.42DEV baseline failed n 295 median tokens 589 mean repetition 0.413 mean final markers 30.74Layer 0 top failure neuron 1869 length-controlled corr 0.202 raw corr 0.211 repeat corr 0.062Layer 1 top failure neuron 483 length-controlled corr 0.172 raw corr 0.185 repeat corr 0.117Layer 2 top failure neuron 1029 length-controlled corr 0.167 raw corr 0.186 repeat corr 0.022Layer 3 top failure neuron 1049 length-controlled corr 0.157 raw corr 0.197 repeat corr 0.068Layer 4 top failure neuron 193 length-controlled corr 0.193 raw corr 0.219 repeat corr 0.018Layer 5 top failure neuron 1427 length-controlled corr 0.167 raw corr 0.164 repeat corr 0.039Layer 6 top failure neuron 2027 length-controlled corr 0.144 raw corr 0.13 repeat corr -0.081Layer 7 top failure neuron 906 length-controlled corr 0.162 raw corr 0.15 repeat corr 0.155Layer 8 top failure neuron 1777 length-controlled corr 0.18 raw corr 0.152 repeat corr -0.169Layer 9 top failure neuron 1006 length-controlled corr 0.152 raw corr 0.138 repeat corr -0.032Layer 10 top failure neuron 482 length-controlled corr 0.159 raw corr 0.186 repeat corr 0.18Layer 11 top failure neuron 401 length-controlled corr 0.213 raw corr 0.236 repeat corr -0.079Layer 12 top failure neuron 1184 length-controlled corr 0.17 raw corr 0.149 repeat corr 0.001Layer 13 top failure neuron 1226 length-controlled corr 0.216 raw corr 0.248 repeat corr -0.026Layer 14 top failure neuron 1497 length-controlled corr 0.182 raw corr 0.149 repeat corr 0.131Layer 15 top failure neuron 1839 length-controlled corr 0.173 raw corr 0.215 repeat corr 0.058Layer 16 top failure neuron 624 length-controlled corr 0.188 raw corr 0.223 repeat corr 0.186Layer 17 top failure neuron 793 length-controlled corr 0.218 raw corr 0.162 repeat corr -0.042Top 16 neurons:{'layer': 17, 'neuron': 793, 'failure_corr': 0.2185, 'raw_failure_corr': 0.1621, 'repeat_corr': -0.0417, 'energy': 0.0035, 'mean': 0.0066, 'sd': 0.006}{'layer': 13, 'neuron': 1226, 'failure_corr': 0.2165, 'raw_failure_corr': 0.248, 'repeat_corr': -0.0262, 'energy': 0.0106, 'mean': 0.0276, 'sd': 0.0113}{'layer': 11, 'neuron': 401, 'failure_corr': 0.2126, 'raw_failure_corr': 0.2361, 'repeat_corr': -0.0788, 'energy': 0.006, 'mean': -0.0078, 'sd': 0.0106}{'layer': 0, 'neuron': 1869, 'failure_corr': 0.2024, 'raw_failure_corr': 0.2113, 'repeat_corr': 0.0622, 'energy': 0.0293, 'mean': 0.0473, 'sd': 0.028}{'layer': 4, 'neuron': 193, 'failure_corr': 0.193, 'raw_failure_corr': 0.2191, 'repeat_corr': 0.0177, 'energy': 0.011, 'mean': 0.0275, 'sd': 0.0181}{'layer': 17, 'neuron': 271, 'failure_corr': 0.1888, 'raw_failure_corr': 0.1946, 'repeat_corr': -0.0406, 'energy': 0.0057, 'mean': -0.0018, 'sd': 0.0125}{'layer': 16, 'neuron': 624, 'failure_corr': 0.1879, 'raw_failure_corr': 0.2233, 'repeat_corr': 0.1856, 'energy': 0.0034, 'mean': -0.0048, 'sd': 0.0061}{'layer': 13, 'neuron': 1540, 'failure_corr': 0.1867, 'raw_failure_corr': 0.1788, 'repeat_corr': 0.1371, 'energy': 0.0057, 'mean': 0.0148, 'sd': 0.0088}{'layer': 14, 'neuron': 1497, 'failure_corr': 0.1817, 'raw_failure_corr': 0.1495, 'repeat_corr': 0.1306, 'energy': 0.0065, 'mean': 0.0133, 'sd': 0.012}{'layer': 13, 'neuron': 223, 'failure_corr': 0.1815, 'raw_failure_corr': 0.184, 'repeat_corr': 0.072, 'energy': 0.0094, 'mean': -0.0072, 'sd': 0.0231}{'layer': 8, 'neuron': 1777, 'failure_corr': 0.1801, 'raw_failure_corr': 0.1522, 'repeat_corr': -0.1692, 'energy': 0.0037, 'mean': 0.0027, 'sd': 0.0107}{'layer': 0, 'neuron': 445, 'failure_corr': 0.1774, 'raw_failure_corr': 0.1913, 'repeat_corr': 0.1654, 'energy': 0.1163, 'mean': 0.0934, 'sd': 0.2129}{'layer': 14, 'neuron': 1202, 'failure_corr': 0.1765, 'raw_failure_corr': 0.2095, 'repeat_corr': 0.0188, 'energy': 0.0068, 'mean': 0.013, 'sd': 0.0141}{'layer': 17, 'neuron': 653, 'failure_corr': 0.1748, 'raw_failure_corr': 0.1051, 'repeat_corr': 0.1539, 'energy': 0.0163, 'mean': 0.0375, 'sd': 0.0095}{'layer': 16, 'neuron': 250, 'failure_corr': 0.1747, 'raw_failure_corr': 0.1778, 'repeat_corr': 0.1508, 'energy': 0.0033, 'mean': -0.004, 'sd': 0.0056}{'layer': 15, 'neuron': 1839, 'failure_corr': 0.1732, 'raw_failure_corr': 0.2145, 'repeat_corr': 0.0579, 'energy': 0.0037, 'mean': -0.0098, 'sd': 0.0087}Short excerpts from DEV failures with no extracted answer:math_train_prealgebra_55 tokens 386 'Let $x = 5^2 - 4^2 = 5^2 - 4^2 = 25 - 16 = 9$.\nThen,\n$\\left(5^2 - 4^2\\right)^3 = (5^2 - 4^2)^3 = (5^2 - 4^2)^3 = (5^2 - 4^2)^3 = (5^2 - 4^2) ... d $9 = 9$, we can say that the value of the expression is 9.\n\nFinal Answer: 9\n\nTherefore, the value of the expression is 9.\n\nFinal Answer: 9'math_train_prealgebra_55 tokens 245 'Let $a = 5^2 - 4^2$.\nWe have $a = 5^2 - 4^2 = 25 - 16 = 9$.\nWe are asked to find the value of $\\left(5^2 - 4^2\\right)^3$.\nWe have\n$$ \\left(5 ... ession as $5^2 - 4^2$.\nThen, we have $5^2 - 4^2 = 25 - 16 = 9$.\nSo the value of the expression is $9$.\n\nFinal Answer: $9$\n\nFinal Answer: $9$'math_train_prealgebra_55 tokens 7964 'Let $x = 5^2 - 4^2$.\nWe have $x = 5^2 - 4^2 = 25 - 16 = 9$.\nWe want to find the value of the expression $\\left(5^2 - 4^2\\right)^3$.\nWe have  ... = 9 \\cdot 9^3.\n\nFinal Answer: 9 \\cdot 9^3 = 9 \\cdot 9^3.\n\nFinal Answer: 9 \\cdot 9^3 = 9 \\cdot 9^3.\n\nFinal Answer: 9 \\cdot 9^3 = 9 \\cdot 9^3.'math_train_prealgebra_55 tokens 549 'Let $a = 5^2 - 4^2 = 5^2 - 4^2 = 25 - 16 = 9$.\nThen we have\n$$ \\left(5^2-4^2\\right)^3 = (9)^3 = 9 \\cdot 9^3 = 9 \\cdot 9^3 = 9 \\cdot 9^6 = 9  ... 9^6$.\nThe expression is $9^6 = 9^6$.\n\nFinal Answer: 9^6\n\n$9^6 = 9^6 = 9^6$\n\nThe value of the expression is $9^6$.\n\nFinal Answer: $9^6 = 9^6$'math_train_prealgebra_55 tokens 94 'To find the value of the expression $(5^2-4^2)^3$, we first evaluate the expression:\n$$ (5^2-4^2)^3 = (5^2-4^2)^3 = (5^2-4^2)^3 = (5-4)^3 =  ... expression:\n$$ (5^2-4^2)^3 = (5^2-4^2)^3 = (5^2-4^2)^3 = (5-4)^3 = 1^3 = 1 $$\nTherefore, the value of the expression is 1.\n\nFinal Answer: 1\n'math_train_prealgebra_774 tokens 157 'Let $a = 5^2 - 3(4) + 3^2$.\n$a = 5^2 - 3(4) + 3^2 = 25 - 12 + 9 = 25 - 3 + 9 = 22 + 9 = 31$.\nTherefore, $5^2-3(4)+3^2 = 31$.\n\nSo the answer  ... -3(4)+3^2 = 31$.\n\nSo the answer is 31.\n\nWe can also write the expression as $5^2-3(4)+3^2 = 25-12+9 = 25-3+9 = 22+9 = 31$.\n\nFinal Answer: 31'DEV IDs: ["math_train_counting_and_probability_606", "math_train_prealgebra_593", "math_train_algebra_1707", "math_train_prealgebra_55", "math_train_prealgebra_940", "math_train_algebra_1114", "math_train_intermediate_algebra_633", "math_train_prealgebra_207", "math_train_prealgebra_502", "math_train_precalculus_220", "math_train_algebra_498", "math_train_algebra_636", "math_train_counting_and_probability_148", "math_train_prealgebra_318", "math_train_prealgebra_780", "math_train_algebra_1497", "math_train_algebra_182", "math_train_intermediate_algebra_643", "math_train_intermediate_algebra_933", "math_train_number_theory_540", "math_train_number_theory_696", "math_train_prealgebra_774", "math_train_algebra_1461", "math_train_algebra_1523", "math_train_algebra_731", "math_train_algebra_958", "math_train_geometry_158", "math_train_intermediate_algebra_80", "math_train_prealgebra_202", "math_train_prealgebra_590", "math_train_prealgebra_839", "math_train_algebra_1423"]

DEV is now fixed, with 217 correct and 295 failed baseline samples. Failed responses are somewhat longer and more repetitive, but the strongest length-controlled neuron–failure correlations are only about 0.22; selecting the largest correlation alone would risk chasing noise. I’ll check whether those associations persist across separate halves of DEV and look for stronger links to repeated, non-progressing reasoning. I’ll also count cases where a response abandons a correct boxed result. These checks will help distinguish a plausible failure mechanism from a general difficulty signal before teacher-forced localization.

python

def normalized_answer(s):    if s is None:        return None    return re.sub(r"[\s$]", "", str(s)).replace(r"\dfrac", r"\frac")
def boxed_contents(text):    out = []    for m in re.finditer(r"\\boxed\s*\{", text):        start, depth, j = m.end(), 1, m.end()        while j < len(text) and depth:            depth += (text[j] == "{") - (text[j] == "}")            j += 1        if depth == 0:            out.append(text[start:j-1])    return out
box_stats = collections.Counter()for r in dev_records:    boxes = boxed_contents(r["text"])    ref = normalized_answer(r["reference"])    matches = [normalized_answer(b) == ref for b in boxes]    box_stats["responses_with_box"] += bool(boxes)    box_stats["multiple_boxes"] += len(boxes) > 1    box_stats["correct_box_then_wrong_last_box"] += (        bool(matches) and any(matches[:-1]) and not matches[-1]    )    box_stats["failed_despite_earlier_matching_box"] += (        not r["correct"] and any(matches[:-1])    )print("DEV box diagnostics:", dict(box_stats))
# Stability across disjoint halves of the DEV problems.for layer in range(18):    X = np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64)    Xc = within_problem(X)    for half in [0, 1]:        mask = groups_dev % 2 == half        z = loglen[mask]        Y = Xc[mask] - np.outer(z, z @ Xc[mask] / (z @ z))        f = failure[mask] - z * (z @ failure[mask]) / (z @ z)        rr = (f @ Y) / (            np.linalg.norm(f) * np.sqrt(np.sum(Y*Y, axis=0) + 1e-20)        )        for s in neuron_screen:            if s["layer"] == layer:                s[f"half{half}_corr"] = float(rr[s["neuron"]])
stable = [    s for s in neuron_screen    if s["half0_corr"] > .06 and s["half1_corr"] > .06    and s["failure_corr"] > .10 and s["mean"] > 0]for s in stable:    s["robust_score"] = min(s["half0_corr"], s["half1_corr"]) * math.sqrt(s["energy"])stable.sort(key=lambda s: s["robust_score"], reverse=True)
print("Stable, positive-mean failure-associated components:")for s in stable[:18]:    print({k: round(s[k], 4) if isinstance(s[k], float) else s[k]           for k in ["layer","neuron","failure_corr","half0_corr","half1_corr",                     "repeat_corr","energy","mean"]})
print("Strongest length-controlled repetition associations:")for s in sorted(neuron_screen, key=lambda s: s["repeat_corr"], reverse=True)[:12]:    print({k: round(s[k], 4) if isinstance(s[k], float) else s[k]           for k in ["layer","neuron","repeat_corr","failure_corr","energy","mean"]})
print("Matched failing DEV excerpts:")for pid in dev_ids[:6]:    rr = [r for r in dev_records if r["problem_id"] == pid and not r["correct"]]    r = min(rr, key=lambda x: abs(x["tokens"] - 500))    print(pid, "reference", ascii(str(practice[pid]["answer"])[:60]),          "response", ascii(r["text"][:140] + " ... " + r["text"][-140:]))
with open("/work/neuron_screen.json", "w") as f:    json.dump(neuron_screen, f)print("No edits; holdout remains untouched.")

def normalized_answer(s):    if s is None:        return None    return re.sub(r"[\s$]", "", str(s)).replace(r"\dfrac", r"\frac")
def boxed_contents(text):    out = []    for m in re.finditer(r"\\boxed\s*\{", text):        start, depth, j = m.end(), 1, m.end()        while j < len(text) and depth:            depth += (text[j] == "{") - (text[j] == "}")            j += 1        if depth == 0:            out.append(text[start:j-1])    return out
box_stats = collections.Counter()for r in dev_records:    boxes = boxed_contents(r["text"])    ref = normalized_answer(r["reference"])    matches = [normalized_answer(b) == ref for b in boxes]    box_stats["responses_with_box"] += bool(boxes)    box_stats["multiple_boxes"] += len(boxes) > 1    box_stats["correct_box_then_wrong_last_box"] += (        bool(matches) and any(matches[:-1]) and not matches[-1]    )    box_stats["failed_despite_earlier_matching_box"] += (        not r["correct"] and any(matches[:-1])    )print("DEV box diagnostics:", dict(box_stats))
# Stability across disjoint halves of the DEV problems.for layer in range(18):    X = np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64)    Xc = within_problem(X)    for half in [0, 1]:        mask = groups_dev % 2 == half        z = loglen[mask]        Y = Xc[mask] - np.outer(z, z @ Xc[mask] / (z @ z))        f = failure[mask] - z * (z @ failure[mask]) / (z @ z)        rr = (f @ Y) / (            np.linalg.norm(f) * np.sqrt(np.sum(Y*Y, axis=0) + 1e-20)        )        for s in neuron_screen:            if s["layer"] == layer:                s[f"half{half}_corr"] = float(rr[s["neuron"]])
stable = [    s for s in neuron_screen    if s["half0_corr"] > .06 and s["half1_corr"] > .06    and s["failure_corr"] > .10 and s["mean"] > 0]for s in stable:    s["robust_score"] = min(s["half0_corr"], s["half1_corr"]) * math.sqrt(s["energy"])stable.sort(key=lambda s: s["robust_score"], reverse=True)
print("Stable, positive-mean failure-associated components:")for s in stable[:18]:    print({k: round(s[k], 4) if isinstance(s[k], float) else s[k]           for k in ["layer","neuron","failure_corr","half0_corr","half1_corr",                     "repeat_corr","energy","mean"]})
print("Strongest length-controlled repetition associations:")for s in sorted(neuron_screen, key=lambda s: s["repeat_corr"], reverse=True)[:12]:    print({k: round(s[k], 4) if isinstance(s[k], float) else s[k]           for k in ["layer","neuron","repeat_corr","failure_corr","energy","mean"]})
print("Matched failing DEV excerpts:")for pid in dev_ids[:6]:    rr = [r for r in dev_records if r["problem_id"] == pid and not r["correct"]]    r = min(rr, key=lambda x: abs(x["tokens"] - 500))    print(pid, "reference", ascii(str(practice[pid]["answer"])[:60]),          "response", ascii(r["text"][:140] + " ... " + r["text"][-140:]))
with open("/work/neuron_screen.json", "w") as f:    json.dump(neuron_screen, f)print("No edits; holdout remains untouched.")

OUTPUT of Python run 6 of at most 300:

DEV box diagnostics: {'responses_with_box': 229, 'multiple_boxes': 8, 'correct_box_then_wrong_last_box': 0, 'failed_despite_earlier_matching_box': 0}Stable, positive-mean failure-associated components:{'layer': 0, 'neuron': 1405, 'failure_corr': 0.1013, 'half0_corr': 0.1063, 'half1_corr': 0.0906, 'repeat_corr': 0.2692, 'energy': 4.2313, 'mean': 13.3728}{'layer': 0, 'neuron': 149, 'failure_corr': 0.105, 'half0_corr': 0.1122, 'half1_corr': 0.0964, 'repeat_corr': 0.2817, 'energy': 0.7672, 'mean': 1.5894}{'layer': 0, 'neuron': 1309, 'failure_corr': 0.1658, 'half0_corr': 0.1908, 'half1_corr': 0.1287, 'repeat_corr': -0.0447, 'energy': 0.2515, 'mean': 0.4785}{'layer': 0, 'neuron': 2032, 'failure_corr': 0.1402, 'half0_corr': 0.1364, 'half1_corr': 0.1399, 'repeat_corr': 0.0226, 'energy': 0.1355, 'mean': 0.1692}{'layer': 0, 'neuron': 761, 'failure_corr': 0.1136, 'half0_corr': 0.1126, 'half1_corr': 0.0989, 'repeat_corr': -0.007, 'energy': 0.2207, 'mean': 0.3206}{'layer': 0, 'neuron': 1479, 'failure_corr': 0.1131, 'half0_corr': 0.1111, 'half1_corr': 0.1212, 'repeat_corr': -0.0276, 'energy': 0.1453, 'mean': 0.1645}{'layer': 0, 'neuron': 1658, 'failure_corr': 0.1098, 'half0_corr': 0.0837, 'half1_corr': 0.1307, 'repeat_corr': -0.0128, 'energy': 0.2551, 'mean': 0.4254}{'layer': 0, 'neuron': 445, 'failure_corr': 0.1774, 'half0_corr': 0.1238, 'half1_corr': 0.2154, 'repeat_corr': 0.1654, 'energy': 0.1163, 'mean': 0.0934}{'layer': 0, 'neuron': 898, 'failure_corr': 0.1156, 'half0_corr': 0.1303, 'half1_corr': 0.1058, 'repeat_corr': 0.1001, 'energy': 0.1486, 'mean': 0.0638}{'layer': 0, 'neuron': 845, 'failure_corr': 0.1108, 'half0_corr': 0.1269, 'half1_corr': 0.0809, 'repeat_corr': 0.062, 'energy': 0.2212, 'mean': 0.2508}{'layer': 1, 'neuron': 483, 'failure_corr': 0.1725, 'half0_corr': 0.2164, 'half1_corr': 0.1222, 'repeat_corr': 0.1173, 'energy': 0.0796, 'mean': 0.1955}{'layer': 1, 'neuron': 1899, 'failure_corr': 0.131, 'half0_corr': 0.0978, 'half1_corr': 0.1538, 'repeat_corr': 0.0744, 'energy': 0.123, 'mean': 0.2215}{'layer': 0, 'neuron': 607, 'failure_corr': 0.1116, 'half0_corr': 0.1151, 'half1_corr': 0.0902, 'repeat_corr': 0.1704, 'energy': 0.1334, 'mean': 0.0462}{'layer': 0, 'neuron': 798, 'failure_corr': 0.1318, 'half0_corr': 0.1282, 'half1_corr': 0.1358, 'repeat_corr': -0.0088, 'energy': 0.0623, 'mean': 0.0027}{'layer': 0, 'neuron': 1632, 'failure_corr': 0.1463, 'half0_corr': 0.1321, 'half1_corr': 0.1547, 'repeat_corr': 0.0959, 'energy': 0.0533, 'mean': 0.0196}{'layer': 0, 'neuron': 1915, 'failure_corr': 0.1299, 'half0_corr': 0.1667, 'half1_corr': 0.1072, 'repeat_corr': 0.2637, 'energy': 0.0808, 'mean': 0.0971}{'layer': 0, 'neuron': 1028, 'failure_corr': 0.1095, 'half0_corr': 0.1097, 'half1_corr': 0.0948, 'repeat_corr': -0.0809, 'energy': 0.1002, 'mean': 0.1064}{'layer': 1, 'neuron': 553, 'failure_corr': 0.1144, 'half0_corr': 0.1015, 'half1_corr': 0.1195, 'repeat_corr': 0.063, 'energy': 0.087, 'mean': 0.1896}Strongest length-controlled repetition associations:{'layer': 5, 'neuron': 1574, 'repeat_corr': 0.445, 'failure_corr': 0.0374, 'energy': 0.0268, 'mean': 0.0608}{'layer': 10, 'neuron': 175, 'repeat_corr': 0.4343, 'failure_corr': 0.0493, 'energy': 0.0189, 'mean': 0.0586}{'layer': 5, 'neuron': 1586, 'repeat_corr': 0.432, 'failure_corr': 0.0061, 'energy': 0.0371, 'mean': -0.0436}{'layer': 5, 'neuron': 1777, 'repeat_corr': 0.4079, 'failure_corr': 0.0377, 'energy': 0.0614, 'mean': 0.1245}{'layer': 16, 'neuron': 452, 'repeat_corr': 0.3941, 'failure_corr': 0.0504, 'energy': 0.0045, 'mean': 0.0013}{'layer': 6, 'neuron': 1142, 'repeat_corr': 0.3879, 'failure_corr': 0.038, 'energy': 0.0257, 'mean': -0.0543}{'layer': 8, 'neuron': 716, 'repeat_corr': 0.3603, 'failure_corr': 0.0521, 'energy': 0.024, 'mean': 0.0765}{'layer': 17, 'neuron': 17, 'repeat_corr': 0.3487, 'failure_corr': -0.0001, 'energy': 0.0093, 'mean': -0.0191}{'layer': 15, 'neuron': 1254, 'repeat_corr': 0.3458, 'failure_corr': -0.0136, 'energy': 0.0084, 'mean': -0.0165}{'layer': 10, 'neuron': 1413, 'repeat_corr': 0.3451, 'failure_corr': -0.0137, 'energy': 0.0119, 'mean': 0.0025}{'layer': 0, 'neuron': 1808, 'repeat_corr': 0.3424, 'failure_corr': 0.0614, 'energy': 0.6438, 'mean': -0.975}{'layer': 8, 'neuron': 916, 'repeat_corr': 0.3389, 'failure_corr': 0.0018, 'energy': 0.017, 'mean': -0.033}Matched failing DEV excerpts:math_train_counting_and_probability_606 reference '35' response 'Let the 7 distinct points be denoted by $P_1, P_2, P_3, P_4, P_5, P_6, P_7$.\nWe want to find the number of different triangles that can be f ... ent triangles that can be formed is 245.\n\nFinal Answer: 245\n\nThe number of different triangles that can be formed is 245.\n\nFinal Answer: 245'math_train_prealgebra_593 reference '250' response 'Let $A=(0,0)$, $B=(25,0)$, and $C=(0,20)$. The area of triangle $ABC$ is given by the formula\n$$Area = \\frac{1}{2} \\cdot AC \\cdot AB = \\frac ... ot 20 \\cdot 25 = \\frac{2500}{2} = 1250.$$\nThus, the area of triangle $ABC$ is 1250 cm$^2$.\n\nFinal Answer: The final answer is $\\boxed{1250}$'math_train_algebra_1707 reference '\\frac{63}{64}' response 'Let the geometric sequence be denoted by $a_1, a_2, a_3, \\dots$.\nThe first term is $a_1 = \\frac12$.\nThe common ratio is $r = \\frac{1}{2}$.\nT ... c{1}{12} + \\frac{1}{16}$.\n\nFinal Answer: The final answer is $\\boxed{\\frac{1}{2} + \\frac{1}{4} + \\frac{1}{8} + \\frac{1}{12} + \\frac{1}{16}}$'math_train_prealgebra_55 reference '729' response 'Let $a = 5^2 - 4^2 = 5^2 - 4^2 = 25 - 16 = 9$.\nThen we have\n$$ \\left(5^2-4^2\\right)^3 = (9)^3 = 9 \\cdot 9^3 = 9 \\cdot 9^3 = 9 \\cdot 9^6 = 9  ... 9^6$.\nThe expression is $9^6 = 9^6$.\n\nFinal Answer: 9^6\n\n$9^6 = 9^6 = 9^6$\n\nThe value of the expression is $9^6$.\n\nFinal Answer: $9^6 = 9^6$'math_train_prealgebra_940 reference '8' response 'Let $n$ be the number of cards Jasmine wants to buy.\nThe cost of the cards is $0.85 per card.\nThe total cost of the cards is $7.50.\nThe tota ... r of cards she can buy is $n = \\frac{75}{85}$.\nThus, the most number of cards she can buy is $\\frac{75}{85}$.\n\nFinal Answer: $\\frac{75}{85}$'math_train_algebra_1114 reference '100' response 'The first 10 odd positive integers are 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21.\nThe sum of the first 10 odd positive integers is\n1 + 3 + 5 + 7 ... irst 10 odd positive integers are 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21.\nTheir sum is $1+3+5+7+9+11+13+15+17+19+21 = 55$.\n\nFinal Answer: 55\n'No edits; holdout remains untouched.

DEV box diagnostics: {'responses_with_box': 229, 'multiple_boxes': 8, 'correct_box_then_wrong_last_box': 0, 'failed_despite_earlier_matching_box': 0}Stable, positive-mean failure-associated components:{'layer': 0, 'neuron': 1405, 'failure_corr': 0.1013, 'half0_corr': 0.1063, 'half1_corr': 0.0906, 'repeat_corr': 0.2692, 'energy': 4.2313, 'mean': 13.3728}{'layer': 0, 'neuron': 149, 'failure_corr': 0.105, 'half0_corr': 0.1122, 'half1_corr': 0.0964, 'repeat_corr': 0.2817, 'energy': 0.7672, 'mean': 1.5894}{'layer': 0, 'neuron': 1309, 'failure_corr': 0.1658, 'half0_corr': 0.1908, 'half1_corr': 0.1287, 'repeat_corr': -0.0447, 'energy': 0.2515, 'mean': 0.4785}{'layer': 0, 'neuron': 2032, 'failure_corr': 0.1402, 'half0_corr': 0.1364, 'half1_corr': 0.1399, 'repeat_corr': 0.0226, 'energy': 0.1355, 'mean': 0.1692}{'layer': 0, 'neuron': 761, 'failure_corr': 0.1136, 'half0_corr': 0.1126, 'half1_corr': 0.0989, 'repeat_corr': -0.007, 'energy': 0.2207, 'mean': 0.3206}{'layer': 0, 'neuron': 1479, 'failure_corr': 0.1131, 'half0_corr': 0.1111, 'half1_corr': 0.1212, 'repeat_corr': -0.0276, 'energy': 0.1453, 'mean': 0.1645}{'layer': 0, 'neuron': 1658, 'failure_corr': 0.1098, 'half0_corr': 0.0837, 'half1_corr': 0.1307, 'repeat_corr': -0.0128, 'energy': 0.2551, 'mean': 0.4254}{'layer': 0, 'neuron': 445, 'failure_corr': 0.1774, 'half0_corr': 0.1238, 'half1_corr': 0.2154, 'repeat_corr': 0.1654, 'energy': 0.1163, 'mean': 0.0934}{'layer': 0, 'neuron': 898, 'failure_corr': 0.1156, 'half0_corr': 0.1303, 'half1_corr': 0.1058, 'repeat_corr': 0.1001, 'energy': 0.1486, 'mean': 0.0638}{'layer': 0, 'neuron': 845, 'failure_corr': 0.1108, 'half0_corr': 0.1269, 'half1_corr': 0.0809, 'repeat_corr': 0.062, 'energy': 0.2212, 'mean': 0.2508}{'layer': 1, 'neuron': 483, 'failure_corr': 0.1725, 'half0_corr': 0.2164, 'half1_corr': 0.1222, 'repeat_corr': 0.1173, 'energy': 0.0796, 'mean': 0.1955}{'layer': 1, 'neuron': 1899, 'failure_corr': 0.131, 'half0_corr': 0.0978, 'half1_corr': 0.1538, 'repeat_corr': 0.0744, 'energy': 0.123, 'mean': 0.2215}{'layer': 0, 'neuron': 607, 'failure_corr': 0.1116, 'half0_corr': 0.1151, 'half1_corr': 0.0902, 'repeat_corr': 0.1704, 'energy': 0.1334, 'mean': 0.0462}{'layer': 0, 'neuron': 798, 'failure_corr': 0.1318, 'half0_corr': 0.1282, 'half1_corr': 0.1358, 'repeat_corr': -0.0088, 'energy': 0.0623, 'mean': 0.0027}{'layer': 0, 'neuron': 1632, 'failure_corr': 0.1463, 'half0_corr': 0.1321, 'half1_corr': 0.1547, 'repeat_corr': 0.0959, 'energy': 0.0533, 'mean': 0.0196}{'layer': 0, 'neuron': 1915, 'failure_corr': 0.1299, 'half0_corr': 0.1667, 'half1_corr': 0.1072, 'repeat_corr': 0.2637, 'energy': 0.0808, 'mean': 0.0971}{'layer': 0, 'neuron': 1028, 'failure_corr': 0.1095, 'half0_corr': 0.1097, 'half1_corr': 0.0948, 'repeat_corr': -0.0809, 'energy': 0.1002, 'mean': 0.1064}{'layer': 1, 'neuron': 553, 'failure_corr': 0.1144, 'half0_corr': 0.1015, 'half1_corr': 0.1195, 'repeat_corr': 0.063, 'energy': 0.087, 'mean': 0.1896}Strongest length-controlled repetition associations:{'layer': 5, 'neuron': 1574, 'repeat_corr': 0.445, 'failure_corr': 0.0374, 'energy': 0.0268, 'mean': 0.0608}{'layer': 10, 'neuron': 175, 'repeat_corr': 0.4343, 'failure_corr': 0.0493, 'energy': 0.0189, 'mean': 0.0586}{'layer': 5, 'neuron': 1586, 'repeat_corr': 0.432, 'failure_corr': 0.0061, 'energy': 0.0371, 'mean': -0.0436}{'layer': 5, 'neuron': 1777, 'repeat_corr': 0.4079, 'failure_corr': 0.0377, 'energy': 0.0614, 'mean': 0.1245}{'layer': 16, 'neuron': 452, 'repeat_corr': 0.3941, 'failure_corr': 0.0504, 'energy': 0.0045, 'mean': 0.0013}{'layer': 6, 'neuron': 1142, 'repeat_corr': 0.3879, 'failure_corr': 0.038, 'energy': 0.0257, 'mean': -0.0543}{'layer': 8, 'neuron': 716, 'repeat_corr': 0.3603, 'failure_corr': 0.0521, 'energy': 0.024, 'mean': 0.0765}{'layer': 17, 'neuron': 17, 'repeat_corr': 0.3487, 'failure_corr': -0.0001, 'energy': 0.0093, 'mean': -0.0191}{'layer': 15, 'neuron': 1254, 'repeat_corr': 0.3458, 'failure_corr': -0.0136, 'energy': 0.0084, 'mean': -0.0165}{'layer': 10, 'neuron': 1413, 'repeat_corr': 0.3451, 'failure_corr': -0.0137, 'energy': 0.0119, 'mean': 0.0025}{'layer': 0, 'neuron': 1808, 'repeat_corr': 0.3424, 'failure_corr': 0.0614, 'energy': 0.6438, 'mean': -0.975}{'layer': 8, 'neuron': 916, 'repeat_corr': 0.3389, 'failure_corr': 0.0018, 'energy': 0.017, 'mean': -0.033}Matched failing DEV excerpts:math_train_counting_and_probability_606 reference '35' response 'Let the 7 distinct points be denoted by $P_1, P_2, P_3, P_4, P_5, P_6, P_7$.\nWe want to find the number of different triangles that can be f ... ent triangles that can be formed is 245.\n\nFinal Answer: 245\n\nThe number of different triangles that can be formed is 245.\n\nFinal Answer: 245'math_train_prealgebra_593 reference '250' response 'Let $A=(0,0)$, $B=(25,0)$, and $C=(0,20)$. The area of triangle $ABC$ is given by the formula\n$$Area = \\frac{1}{2} \\cdot AC \\cdot AB = \\frac ... ot 20 \\cdot 25 = \\frac{2500}{2} = 1250.$$\nThus, the area of triangle $ABC$ is 1250 cm$^2$.\n\nFinal Answer: The final answer is $\\boxed{1250}$'math_train_algebra_1707 reference '\\frac{63}{64}' response 'Let the geometric sequence be denoted by $a_1, a_2, a_3, \\dots$.\nThe first term is $a_1 = \\frac12$.\nThe common ratio is $r = \\frac{1}{2}$.\nT ... c{1}{12} + \\frac{1}{16}$.\n\nFinal Answer: The final answer is $\\boxed{\\frac{1}{2} + \\frac{1}{4} + \\frac{1}{8} + \\frac{1}{12} + \\frac{1}{16}}$'math_train_prealgebra_55 reference '729' response 'Let $a = 5^2 - 4^2 = 5^2 - 4^2 = 25 - 16 = 9$.\nThen we have\n$$ \\left(5^2-4^2\\right)^3 = (9)^3 = 9 \\cdot 9^3 = 9 \\cdot 9^3 = 9 \\cdot 9^6 = 9  ... 9^6$.\nThe expression is $9^6 = 9^6$.\n\nFinal Answer: 9^6\n\n$9^6 = 9^6 = 9^6$\n\nThe value of the expression is $9^6$.\n\nFinal Answer: $9^6 = 9^6$'math_train_prealgebra_940 reference '8' response 'Let $n$ be the number of cards Jasmine wants to buy.\nThe cost of the cards is $0.85 per card.\nThe total cost of the cards is $7.50.\nThe tota ... r of cards she can buy is $n = \\frac{75}{85}$.\nThus, the most number of cards she can buy is $\\frac{75}{85}$.\n\nFinal Answer: $\\frac{75}{85}$'math_train_algebra_1114 reference '100' response 'The first 10 odd positive integers are 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21.\nThe sum of the first 10 odd positive integers is\n1 + 3 + 5 + 7 ... irst 10 odd positive integers are 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21.\nTheir sum is $1+3+5+7+9+11+13+15+17+19+21 = 55$.\n\nFinal Answer: 55\n'No edits; holdout remains untouched.

There were no DEV cases where an earlier correct boxed answer was replaced by a wrong final box, so I won’t pursue that hypothesis. Repetition-associated neurons also have weak accuracy associations, which cautions against treating repetition reduction as the goal. A few early-layer neurons carry much larger contributions and show consistent, though modest, failure associations across both DEV halves. I’ll use teacher forcing on DEV trajectories and reference solutions to see what those neurons actually respond to, especially whether they distinguish unproductive copying from arithmetic progress. This remains localization, not evidence that suppressing them will help.

python

PREFIX = "<bos><start_of_turn>user\n"SUFFIX = (    "\nPlease reason step by step, and put your final answer within \\boxed{}."    "<end_of_turn>\n<start_of_turn>model\n")
teacher_sources = []for i in dev_indices:    r = records[int(i)]    teacher_sources.append({        "kind": "generated", "record_index": int(i), "problem_id": r["problem_id"],        "correct": bool(r["correct"]),        "prompt": PREFIX + practice[r["problem_id"]]["problem"] + SUFFIX,        "answer": r["text"],    })for pid in dev_ids:    teacher_sources.append({        "kind": "reference", "record_index": None, "problem_id": pid,        "correct": True, "prompt": PREFIX + practice[pid]["problem"] + SUFFIX,        "answer": practice[pid]["solution"],    })
encoded_sources = [    tok.encode(s["prompt"] + s["answer"], add_special_tokens=[REDACTED]    for s in teacher_sources]cap = 2048while sum(min(len(e.ids), cap) for e in encoded_sources) > 520000:    cap -= 64
teacher_texts, teacher_manifest = [], []for source, enc in zip(teacher_sources, encoded_sources):    raw = source["prompt"] + source["answer"]    if len(enc.ids) > cap:        raw = raw[:enc.offsets[cap-1][1]]    actual = tok.encode(raw, add_special_tokens=[REDACTED]    assert len(actual.ids) <= cap    teacher_texts.append(raw)    teacher_manifest.append({        k: v for k,v in source.items() if k not in ["prompt", "answer"]    } | {        "prompt_chars": len(source["prompt"]),        "prompt_tokens": len(tok.encode(source["prompt"], add_special_tokens=[REDACTED]        "tokens": len(actual.ids),        "truncated": len(enc.ids) > cap,    })
teacher_return = {    "token_logprobs": True,    "topk": 8,    "hidden_states": [0,1,6,14,18],    "mlp_act": [0,1,5,13,17],}teacher_request = {    "type": "teacher_forced", "model": "original",    "texts": teacher_texts, "return": teacher_return,}with open("/work/dev_teacher_texts.json", "w") as f:    json.dump(teacher_texts, f)with open("/work/dev_teacher_manifest.json", "w") as f:    json.dump(teacher_manifest, f)with open("/work/dev_teacher_request.json", "w") as f:    json.dump(teacher_request, f)
with open("/work/notes.md", "a") as f:    f.write(        "\n## Baseline localization findings\n"        "- 337/2048 correct overall. DEV: 217/512 correct.\n"        "- Wrong quantity binding, invalid arithmetic/algebra, and repeated "        "non-progressing equalities occur in inspected failures.\n"        "- No DEV correct-box-to-wrong-box overwrite cases found.\n"        "- Pure repetition correlations are not strong accuracy evidence.\n"        "- Length-controlled, within-problem failure correlations are modest.\n"        "- Early MLP neurons 1405,149,1309,2032 and others in layer 0 "        "have stable associations across disjoint DEV halves; not yet causal.\n"        "\n## Pass 2: original teacher-forced localization\n"        "- Exact edit: none; original weights.\n"        "- Dataset: all 512 DEV sampled responses plus 32 DEV reference "        "solutions, truncated only for the forward token budget.\n"        "- Full request: dev_teacher_request.json; text list: dev_teacher_texts.json; "        "alignment: dev_teacher_manifest.json.\n"        f"- Texts: {len(teacher_texts)}; tokens: "        f"{sum(m['tokens'] for m in teacher_manifest)}; cap: {cap}.\n"        "- Examine token-local arithmetic progress versus copied/repeated "        "expressions and component specificity before selecting an edit.\n"    )print("Teacher-forced texts:", len(teacher_texts))print("Total tokens:", sum(m["tokens"] for m in teacher_manifest))print("Maximum tokens:", max(m["tokens"] for m in teacher_manifest))print("Truncated trajectories:", sum(m["truncated"] for m in teacher_manifest))print("Request saved to /work/dev_teacher_request.json.")print("Weights unchanged.")

PREFIX = "<bos><start_of_turn>user\n"SUFFIX = (    "\nPlease reason step by step, and put your final answer within \\boxed{}."    "<end_of_turn>\n<start_of_turn>model\n")
teacher_sources = []for i in dev_indices:    r = records[int(i)]    teacher_sources.append({        "kind": "generated", "record_index": int(i), "problem_id": r["problem_id"],        "correct": bool(r["correct"]),        "prompt": PREFIX + practice[r["problem_id"]]["problem"] + SUFFIX,        "answer": r["text"],    })for pid in dev_ids:    teacher_sources.append({        "kind": "reference", "record_index": None, "problem_id": pid,        "correct": True, "prompt": PREFIX + practice[pid]["problem"] + SUFFIX,        "answer": practice[pid]["solution"],    })
encoded_sources = [    tok.encode(s["prompt"] + s["answer"], add_special_tokens=[REDACTED]    for s in teacher_sources]cap = 2048while sum(min(len(e.ids), cap) for e in encoded_sources) > 520000:    cap -= 64
teacher_texts, teacher_manifest = [], []for source, enc in zip(teacher_sources, encoded_sources):    raw = source["prompt"] + source["answer"]    if len(enc.ids) > cap:        raw = raw[:enc.offsets[cap-1][1]]    actual = tok.encode(raw, add_special_tokens=[REDACTED]    assert len(actual.ids) <= cap    teacher_texts.append(raw)    teacher_manifest.append({        k: v for k,v in source.items() if k not in ["prompt", "answer"]    } | {        "prompt_chars": len(source["prompt"]),        "prompt_tokens": len(tok.encode(source["prompt"], add_special_tokens=[REDACTED]        "tokens": len(actual.ids),        "truncated": len(enc.ids) > cap,    })
teacher_return = {    "token_logprobs": True,    "topk": 8,    "hidden_states": [0,1,6,14,18],    "mlp_act": [0,1,5,13,17],}teacher_request = {    "type": "teacher_forced", "model": "original",    "texts": teacher_texts, "return": teacher_return,}with open("/work/dev_teacher_texts.json", "w") as f:    json.dump(teacher_texts, f)with open("/work/dev_teacher_manifest.json", "w") as f:    json.dump(teacher_manifest, f)with open("/work/dev_teacher_request.json", "w") as f:    json.dump(teacher_request, f)
with open("/work/notes.md", "a") as f:    f.write(        "\n## Baseline localization findings\n"        "- 337/2048 correct overall. DEV: 217/512 correct.\n"        "- Wrong quantity binding, invalid arithmetic/algebra, and repeated "        "non-progressing equalities occur in inspected failures.\n"        "- No DEV correct-box-to-wrong-box overwrite cases found.\n"        "- Pure repetition correlations are not strong accuracy evidence.\n"        "- Length-controlled, within-problem failure correlations are modest.\n"        "- Early MLP neurons 1405,149,1309,2032 and others in layer 0 "        "have stable associations across disjoint DEV halves; not yet causal.\n"        "\n## Pass 2: original teacher-forced localization\n"        "- Exact edit: none; original weights.\n"        "- Dataset: all 512 DEV sampled responses plus 32 DEV reference "        "solutions, truncated only for the forward token budget.\n"        "- Full request: dev_teacher_request.json; text list: dev_teacher_texts.json; "        "alignment: dev_teacher_manifest.json.\n"        f"- Texts: {len(teacher_texts)}; tokens: "        f"{sum(m['tokens'] for m in teacher_manifest)}; cap: {cap}.\n"        "- Examine token-local arithmetic progress versus copied/repeated "        "expressions and component specificity before selecting an edit.\n"    )print("Teacher-forced texts:", len(teacher_texts))print("Total tokens:", sum(m["tokens"] for m in teacher_manifest))print("Maximum tokens:", max(m["tokens"] for m in teacher_manifest))print("Truncated trajectories:", sum(m["truncated"] for m in teacher_manifest))print("Request saved to /work/dev_teacher_request.json.")print("Weights unchanged.")

OUTPUT of Python run 7 of at most 300:

Teacher-forced texts: 544Total tokens: 427720Maximum tokens: 2048Truncated trajectories: 62Request saved to /work/dev_teacher_request.json.Weights unchanged.

Teacher-forced texts: 544Total tokens: 427720Maximum tokens: 2048Truncated trajectories: 62Request saved to /work/dev_teacher_request.json.Weights unchanged.

The localization batch contains 544 texts and 427,720 tokens: every DEV sample plus every DEV reference solution. Only 62 trajectories needed truncation, and no holdout material or edited weights are included. I’ll submit the saved text list so the large batch does not flood the transcript. Token-level activations should show whether the candidate neurons track specific failure behavior or merely common mathematical formatting.

forward

{"type":"teacher_forced","model":"original","texts_file":"/work/dev_teacher_texts.json","return":{"token_logprobs":true,"topk":8,"hidden_states":[0,1,6,14,18],"mlp_act":[0,1,5,13,17]}}

{"type":"teacher_forced","model":"original","texts_file":"/work/dev_teacher_texts.json","return":{"token_logprobs":true,"topk":8,"hidden_states":[0,1,6,14,18],"mlp_act":[0,1,5,13,17]}}

The forward request is not valid (AssertionError: a teacher-forced pass needs texts or chats). Not counted.

The file-list field was rejected, so no forward pass was spent and there are no new model results. The prepared localization batch and unedited weights remain unchanged. I’ll check whether the required texts field accepts the saved JSON path; this is an input-format check, not a model experiment.

forward

{"type":"teacher_forced","model":"original","texts":"/work/dev_teacher_texts.json","return":{"token_logprobs":true,"topk":8,"hidden_states":[0,1,6,14,18],"mlp_act":[0,1,5,13,17]}}

{"type":"teacher_forced","model":"original","texts":"/work/dev_teacher_texts.json","return":{"token_logprobs":true,"topk":8,"hidden_states":[0,1,6,14,18],"mlp_act":[0,1,5,13,17]}}

Forward pass 2 of 5 done (teacher_forced); results in /work/fwd_2/. Summary:

{ "ok": true, "lengths": [  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1 ], "files": {  "input_ids": [   28,   1  ],  "token_logprobs": [   28,   0  ],  "topk_logprobs": [   28,   1,   8  ],  "topk_ids": [   28,   1,   8  ],  "hidden_0": [   28,   1,   640  ],  "hidden_1": [   28,   1,   640  ],  "hidden_6": [   28,   1,   640  ],  "hidden_14": [   28,   1,   640  ],  "hidden_18": [   28,   1,   640  ],  "mlp_act_0": [   28,   1,   2048  ],  "mlp_act_1": [   28,   1,   2048  ],  "mlp_act_5": [   28,   1,   2048  ],  "mlp_act_13": [   28,   1,   2048  ],  "mlp_act_17": [   28,   1,   2048  ] }, "edited_tensors": 0, "mean_token_logprob": [  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null ], "type": "teacher_forced", "s": 0.6}

{ "ok": true, "lengths": [  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1 ], "files": {  "input_ids": [   28,   1  ],  "token_logprobs": [   28,   0  ],  "topk_logprobs": [   28,   1,   8  ],  "topk_ids": [   28,   1,   8  ],  "hidden_0": [   28,   1,   640  ],  "hidden_1": [   28,   1,   640  ],  "hidden_6": [   28,   1,   640  ],  "hidden_14": [   28,   1,   640  ],  "hidden_18": [   28,   1,   640  ],  "mlp_act_0": [   28,   1,   2048  ],  "mlp_act_1": [   28,   1,   2048  ],  "mlp_act_5": [   28,   1,   2048  ],  "mlp_act_13": [   28,   1,   2048  ],  "mlp_act_17": [   28,   1,   2048  ] }, "edited_tensors": 0, "mean_token_logprob": [  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null,  null ], "type": "teacher_forced", "s": 0.6}

Forward passes left: 3. Edits used in this pass: none (edit hash none).

The tool interpreted the path as 28 separate character strings, so pass 2 did not run the intended localization batch. That was my input-format mistake, and I will not treat its outputs as evidence about math reasoning. Three passes remain, which still allow two full paired DEV tests and a frozen holdout test. I’ll use the valid baseline activations to narrow the hypothesis further by identifying mechanically checkable arithmetic errors and separating them from repetition and formatting. Any resulting edit will need actual generation evidence to support it.

python

import astfrom fractions import Fraction
with open("/work/notes.md", "a") as f:    f.write(        "\n## Pass 2 input-format failure (consumed)\n"        "- texts_file was rejected without cost. Passing a path in texts was "        "incorrectly interpreted as 28 one-character texts, consuming pass 2.\n"        "- Intended 544-text localization batch was NOT run.\n"        "- No token-local math claims will be made from fwd_2 outputs.\n"        "- Remaining plan: two full paired DEV tests at different strengths, "        "then freeze and test HOLDOUT.\n"    )
def safe_number(expr):    expr = expr.strip().rstrip(".,")    if not expr or len(expr) > 180 or not re.fullmatch(r"[0-9\s.+*/()\-]+", expr):        return None    try:        tree = ast.parse(expr, mode="eval")        def rec(node, depth=0):            if depth > 18:                raise ValueError()            if isinstance(node, ast.Expression):                return rec(node.body, depth+1)            if isinstance(node, ast.Constant) and type(node.value) in (int, float):                if abs(node.value) > 1e10:                    raise ValueError()                return Fraction(str(node.value))            if isinstance(node, ast.UnaryOp) and isinstance(node.op, (ast.UAdd, ast.USub)):                val = rec(node.operand, depth+1)                return -val if isinstance(node.op, ast.USub) else val            if isinstance(node, ast.BinOp):                a, b = rec(node.left, depth+1), rec(node.right, depth+1)                if isinstance(node.op, ast.Add): v = a+b                elif isinstance(node.op, ast.Sub): v = a-b                elif isinstance(node.op, ast.Mult): v = a*b                elif isinstance(node.op, ast.Div): v = a/b                elif isinstance(node.op, ast.Pow):                    if b.denominator != 1 or abs(b) > 8: raise ValueError()                    v = a ** int(b)                else: raise ValueError()                if abs(v.numerator) > 10**30 or v.denominator > 10**30:                    raise ValueError()                return v            raise ValueError()        return rec(tree)    except Exception:        return None
def numeric_equalities(text):    spans = re.findall(r"\$\$([\s\S]*?)\$\$|\$([^$\n]+)\$", text)    checked = []    for pair in spans:        s = pair[0] or pair[1]        s = re.sub(r"\\(?:left|right|displaystyle|,|!|;)", "", s)        s = s.replace(r"\times", "*").replace(r"\cdot", "*").replace(r"\div", "/")        for _ in range(5):            s2 = re.sub(r"\\(?:dfrac|frac)\{([^{}]*)\}\{([^{}]*)\}", r"((\1)/(\2))", s)            if s2 == s: break            s = s2        s = s.replace("^", "**").replace("{", "(").replace("}", ")")        parts = s.split("=")        for a, b in zip(parts, parts[1:]):            av, bv = safe_number(a), safe_number(b)            if av is not None and bv is not None:                identical = re.sub(r"\s", "", a) == re.sub(r"\s", "", b)                checked.append((av == bv, identical, a.strip()[:70], b.strip()[:70]))    return checked
feature_rows = []for r in dev_records:    t = r["text"]    eqs = numeric_equalities(t)    bad = sum(not e[0] for e in eqs)    progress = sum(e[0] and not e[1] for e in eqs)    identities = sum(e[1] for e in eqs)    L = max(1, len(t))    feature_rows.append({        "arithmetic_error": bad / max(1, bad + progress),        "arithmetic_error_count": math.log1p(bad),        "arithmetic_progress": progress / max(1, bad + progress + identities),        "identity_fraction": identities / max(1, len(eqs)),        "repetition": r["repeat4"],        "equality_density": t.count("=") / L,        "digit_density": sum(c.isdigit() for c in t) / L,        "latex_density": t.count("\\") / L,        "final_density": r["final_markers"] / max(1, r["tokens"]),        "let_density": len(re.findall(r"\b[Ll]et\b", t)) / max(1, r["tokens"]),        "therefore_density": len(re.findall(r"\b[Tt]herefore\b", t)) / max(1, r["tokens"]),    })feature_names = list(feature_rows[0])F = np.array([[r[k] for k in feature_names] for r in feature_rows])Fc = within_problem(F)Fl = Fc - np.outer(loglen, loglen @ Fc / (loglen @ loglen))Fnorm = np.sqrt(np.sum(Fl * Fl, axis=0) + 1e-20)
print("Mechanical arithmetic checks:",      sum(len(numeric_equalities(r["text"])) for r in dev_records),      "adjacent literal-number equalities")for good in [True, False]:    mask = np.array([r["correct"] == good for r in dev_records])    print("Correct" if good else "Failed",          "responses with checked arithmetic error:",          int(np.sum(F[mask, feature_names.index("arithmetic_error_count")] > 0)),          "/", int(mask.sum()))
component_profiles = {}for layer in [0,1,5,13,17]:    X = np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64)    Xc = within_problem(X)    Xl = Xc - np.outer(loglen, loglen @ Xc / (loglen @ loglen))    corrs = Xl.T @ Fl / (        np.sqrt(np.sum(Xl*Xl, axis=0) + 1e-20)[:,None] * Fnorm[None,:]    )    for s in neuron_screen:        if s["layer"] == layer:            s["feature_corrs"] = dict(zip(feature_names, map(float, corrs[s["neuron"]])))    candidates = sorted(        [s for s in stable if s["layer"] == layer],        key=lambda s: s["robust_score"], reverse=True    )[:6]    for s in candidates:        j = s["neuron"]        profile = sorted(            s["feature_corrs"].items(), key=lambda x: abs(x[1]), reverse=True        )[:4]        print("L", layer, "N", j,              "mean/sd", round(s["mean"],3), round(s["sd"],3),              "top feature correlations", [(k,round(v,3)) for k,v in profile])
arith_candidates = [    s for s in stable    if "feature_corrs" in s and s["feature_corrs"]["arithmetic_error"] > .06]arith_candidates.sort(    key=lambda s: s["robust_score"] * s["feature_corrs"]["arithmetic_error"],    reverse=True)print("Stable failure + arithmetic-error candidates:")for s in arith_candidates[:16]:    print("L", s["layer"], "N", s["neuron"],          "failure", round(s["failure_corr"],3),          "arith-error", round(s["feature_corrs"]["arithmetic_error"],3),          "energy", round(s["energy"],4),          "mean/sd", round(s["mean"],3), round(s["sd"],3))print("Weights remain unchanged.")

import astfrom fractions import Fraction
with open("/work/notes.md", "a") as f:    f.write(        "\n## Pass 2 input-format failure (consumed)\n"        "- texts_file was rejected without cost. Passing a path in texts was "        "incorrectly interpreted as 28 one-character texts, consuming pass 2.\n"        "- Intended 544-text localization batch was NOT run.\n"        "- No token-local math claims will be made from fwd_2 outputs.\n"        "- Remaining plan: two full paired DEV tests at different strengths, "        "then freeze and test HOLDOUT.\n"    )
def safe_number(expr):    expr = expr.strip().rstrip(".,")    if not expr or len(expr) > 180 or not re.fullmatch(r"[0-9\s.+*/()\-]+", expr):        return None    try:        tree = ast.parse(expr, mode="eval")        def rec(node, depth=0):            if depth > 18:                raise ValueError()            if isinstance(node, ast.Expression):                return rec(node.body, depth+1)            if isinstance(node, ast.Constant) and type(node.value) in (int, float):                if abs(node.value) > 1e10:                    raise ValueError()                return Fraction(str(node.value))            if isinstance(node, ast.UnaryOp) and isinstance(node.op, (ast.UAdd, ast.USub)):                val = rec(node.operand, depth+1)                return -val if isinstance(node.op, ast.USub) else val            if isinstance(node, ast.BinOp):                a, b = rec(node.left, depth+1), rec(node.right, depth+1)                if isinstance(node.op, ast.Add): v = a+b                elif isinstance(node.op, ast.Sub): v = a-b                elif isinstance(node.op, ast.Mult): v = a*b                elif isinstance(node.op, ast.Div): v = a/b                elif isinstance(node.op, ast.Pow):                    if b.denominator != 1 or abs(b) > 8: raise ValueError()                    v = a ** int(b)                else: raise ValueError()                if abs(v.numerator) > 10**30 or v.denominator > 10**30:                    raise ValueError()                return v            raise ValueError()        return rec(tree)    except Exception:        return None
def numeric_equalities(text):    spans = re.findall(r"\$\$([\s\S]*?)\$\$|\$([^$\n]+)\$", text)    checked = []    for pair in spans:        s = pair[0] or pair[1]        s = re.sub(r"\\(?:left|right|displaystyle|,|!|;)", "", s)        s = s.replace(r"\times", "*").replace(r"\cdot", "*").replace(r"\div", "/")        for _ in range(5):            s2 = re.sub(r"\\(?:dfrac|frac)\{([^{}]*)\}\{([^{}]*)\}", r"((\1)/(\2))", s)            if s2 == s: break            s = s2        s = s.replace("^", "**").replace("{", "(").replace("}", ")")        parts = s.split("=")        for a, b in zip(parts, parts[1:]):            av, bv = safe_number(a), safe_number(b)            if av is not None and bv is not None:                identical = re.sub(r"\s", "", a) == re.sub(r"\s", "", b)                checked.append((av == bv, identical, a.strip()[:70], b.strip()[:70]))    return checked
feature_rows = []for r in dev_records:    t = r["text"]    eqs = numeric_equalities(t)    bad = sum(not e[0] for e in eqs)    progress = sum(e[0] and not e[1] for e in eqs)    identities = sum(e[1] for e in eqs)    L = max(1, len(t))    feature_rows.append({        "arithmetic_error": bad / max(1, bad + progress),        "arithmetic_error_count": math.log1p(bad),        "arithmetic_progress": progress / max(1, bad + progress + identities),        "identity_fraction": identities / max(1, len(eqs)),        "repetition": r["repeat4"],        "equality_density": t.count("=") / L,        "digit_density": sum(c.isdigit() for c in t) / L,        "latex_density": t.count("\\") / L,        "final_density": r["final_markers"] / max(1, r["tokens"]),        "let_density": len(re.findall(r"\b[Ll]et\b", t)) / max(1, r["tokens"]),        "therefore_density": len(re.findall(r"\b[Tt]herefore\b", t)) / max(1, r["tokens"]),    })feature_names = list(feature_rows[0])F = np.array([[r[k] for k in feature_names] for r in feature_rows])Fc = within_problem(F)Fl = Fc - np.outer(loglen, loglen @ Fc / (loglen @ loglen))Fnorm = np.sqrt(np.sum(Fl * Fl, axis=0) + 1e-20)
print("Mechanical arithmetic checks:",      sum(len(numeric_equalities(r["text"])) for r in dev_records),      "adjacent literal-number equalities")for good in [True, False]:    mask = np.array([r["correct"] == good for r in dev_records])    print("Correct" if good else "Failed",          "responses with checked arithmetic error:",          int(np.sum(F[mask, feature_names.index("arithmetic_error_count")] > 0)),          "/", int(mask.sum()))
component_profiles = {}for layer in [0,1,5,13,17]:    X = np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64)    Xc = within_problem(X)    Xl = Xc - np.outer(loglen, loglen @ Xc / (loglen @ loglen))    corrs = Xl.T @ Fl / (        np.sqrt(np.sum(Xl*Xl, axis=0) + 1e-20)[:,None] * Fnorm[None,:]    )    for s in neuron_screen:        if s["layer"] == layer:            s["feature_corrs"] = dict(zip(feature_names, map(float, corrs[s["neuron"]])))    candidates = sorted(        [s for s in stable if s["layer"] == layer],        key=lambda s: s["robust_score"], reverse=True    )[:6]    for s in candidates:        j = s["neuron"]        profile = sorted(            s["feature_corrs"].items(), key=lambda x: abs(x[1]), reverse=True        )[:4]        print("L", layer, "N", j,              "mean/sd", round(s["mean"],3), round(s["sd"],3),              "top feature correlations", [(k,round(v,3)) for k,v in profile])
arith_candidates = [    s for s in stable    if "feature_corrs" in s and s["feature_corrs"]["arithmetic_error"] > .06]arith_candidates.sort(    key=lambda s: s["robust_score"] * s["feature_corrs"]["arithmetic_error"],    reverse=True)print("Stable failure + arithmetic-error candidates:")for s in arith_candidates[:16]:    print("L", s["layer"], "N", s["neuron"],          "failure", round(s["failure_corr"],3),          "arith-error", round(s["feature_corrs"]["arithmetic_error"],3),          "energy", round(s["energy"],4),          "mean/sd", round(s["mean"],3), round(s["sd"],3))print("Weights remain unchanged.")

OUTPUT of Python run 8 of at most 300:

Mechanical arithmetic checks: 3270 adjacent literal-number equalitiesCorrect responses with checked arithmetic error: 27 / 217Failed responses with checked arithmetic error: 82 / 295L 0 N 1405 mean/sd 13.373 6.971 top feature correlations [('digit_density', 0.318), ('repetition', 0.269), ('final_density', 0.132), ('latex_density', -0.126)]L 0 N 149 mean/sd 1.589 0.596 top feature correlations [('final_density', 0.329), ('repetition', 0.282), ('equality_density', -0.203), ('latex_density', -0.202)]L 0 N 1309 mean/sd 0.479 0.24 top feature correlations [('digit_density', 0.561), ('let_density', -0.144), ('arithmetic_error_count', 0.121), ('final_density', -0.094)]L 0 N 2032 mean/sd 0.169 0.193 top feature correlations [('digit_density', 0.4), ('final_density', -0.27), ('equality_density', 0.166), ('arithmetic_progress', -0.157)]L 0 N 761 mean/sd 0.321 0.277 top feature correlations [('digit_density', 0.59), ('arithmetic_error_count', 0.196), ('latex_density', -0.153), ('let_density', -0.122)]L 0 N 1479 mean/sd 0.165 0.201 top feature correlations [('digit_density', 0.487), ('identity_fraction', 0.177), ('arithmetic_error_count', 0.171), ('final_density', -0.121)]L 1 N 483 mean/sd 0.195 0.114 top feature correlations [('digit_density', 0.664), ('equality_density', 0.192), ('let_density', -0.157), ('arithmetic_error_count', 0.144)]L 1 N 1899 mean/sd 0.222 0.253 top feature correlations [('digit_density', 0.635), ('latex_density', -0.484), ('equality_density', 0.217), ('final_density', 0.141)]L 1 N 553 mean/sd 0.19 0.149 top feature correlations [('digit_density', 0.643), ('arithmetic_progress', -0.139), ('therefore_density', -0.133), ('final_density', -0.129)]L 1 N 421 mean/sd 0.198 0.107 top feature correlations [('digit_density', 0.42), ('equality_density', 0.226), ('latex_density', 0.171), ('arithmetic_error_count', 0.1)]L 1 N 1851 mean/sd 0.132 0.085 top feature correlations [('digit_density', 0.369), ('final_density', 0.316), ('equality_density', 0.134), ('therefore_density', -0.126)]L 1 N 1066 mean/sd 0.053 0.06 top feature correlations [('final_density', 0.442), ('arithmetic_error_count', 0.169), ('identity_fraction', 0.152), ('let_density', -0.109)]L 5 N 1111 mean/sd 0.004 0.018 top feature correlations [('final_density', 0.522), ('equality_density', -0.486), ('latex_density', -0.197), ('repetition', 0.119)]L 5 N 1244 mean/sd 0.052 0.046 top feature correlations [('digit_density', 0.492), ('final_density', -0.254), ('latex_density', 0.181), ('arithmetic_error_count', 0.136)]L 5 N 970 mean/sd 0.037 0.015 top feature correlations [('digit_density', 0.63), ('final_density', -0.23), ('equality_density', 0.167), ('therefore_density', -0.161)]L 5 N 207 mean/sd 0.014 0.013 top feature correlations [('final_density', 0.451), ('digit_density', 0.395), ('latex_density', -0.336), ('equality_density', -0.171)]L 5 N 473 mean/sd 0.022 0.01 top feature correlations [('final_density', 0.345), ('equality_density', -0.236), ('arithmetic_error', -0.141), ('arithmetic_progress', 0.097)]L 5 N 1493 mean/sd 0.013 0.014 top feature correlations [('equality_density', -0.522), ('final_density', 0.502), ('latex_density', -0.264), ('arithmetic_error_count', 0.092)]L 13 N 1226 mean/sd 0.028 0.011 top feature correlations [('digit_density', 0.343), ('equality_density', 0.149), ('arithmetic_progress', -0.128), ('final_density', -0.127)]L 13 N 231 mean/sd 0.035 0.016 top feature correlations [('digit_density', 0.607), ('equality_density', 0.268), ('final_density', -0.221), ('identity_fraction', 0.149)]L 13 N 1881 mean/sd 0.023 0.009 top feature correlations [('digit_density', 0.427), ('equality_density', 0.329), ('final_density', -0.179), ('arithmetic_progress', -0.17)]L 13 N 570 mean/sd 0.033 0.012 top feature correlations [('digit_density', 0.423), ('final_density', -0.304), ('identity_fraction', 0.248), ('latex_density', 0.152)]L 13 N 39 mean/sd 0.053 0.023 top feature correlations [('digit_density', 0.397), ('final_density', -0.38), ('arithmetic_error_count', 0.21), ('latex_density', 0.195)]L 13 N 1059 mean/sd 0.033 0.019 top feature correlations [('equality_density', 0.538), ('digit_density', 0.504), ('final_density', -0.242), ('latex_density', 0.235)]L 17 N 1451 mean/sd 0.183 0.06 top feature correlations [('digit_density', 0.375), ('equality_density', 0.272), ('identity_fraction', 0.264), ('repetition', 0.233)]L 17 N 653 mean/sd 0.037 0.009 top feature correlations [('digit_density', 0.289), ('equality_density', 0.259), ('final_density', -0.22), ('repetition', 0.154)]L 17 N 547 mean/sd 0.083 0.051 top feature correlations [('final_density', 0.375), ('latex_density', -0.373), ('digit_density', 0.275), ('equality_density', 0.264)]L 17 N 942 mean/sd 0.033 0.01 top feature correlations [('final_density', -0.491), ('digit_density', 0.464), ('equality_density', 0.259), ('therefore_density', -0.147)]L 17 N 211 mean/sd 0.067 0.044 top feature correlations [('final_density', 0.341), ('latex_density', -0.294), ('equality_density', -0.208), ('digit_density', -0.19)]L 17 N 1475 mean/sd 0.015 0.015 top feature correlations [('digit_density', 0.184), ('let_density', -0.167), ('identity_fraction', 0.113), ('final_density', -0.105)]Stable failure + arithmetic-error candidates:L 0 N 1028 failure 0.11 arith-error 0.154 energy 0.1002 mean/sd 0.106 0.126L 0 N 2032 failure 0.14 arith-error 0.092 energy 0.1355 mean/sd 0.169 0.193L 0 N 761 failure 0.114 arith-error 0.075 energy 0.2207 mean/sd 0.321 0.277L 0 N 1479 failure 0.113 arith-error 0.063 energy 0.1453 mean/sd 0.165 0.201L 0 N 845 failure 0.111 arith-error 0.066 energy 0.2212 mean/sd 0.251 0.262L 0 N 1450 failure 0.128 arith-error 0.082 energy 0.0428 mean/sd 0.023 0.064L 0 N 1013 failure 0.109 arith-error 0.08 energy 0.0683 mean/sd 0.047 0.116L 13 N 1881 failure 0.168 arith-error 0.117 energy 0.0101 mean/sd 0.023 0.009L 17 N 1554 failure 0.135 arith-error 0.165 energy 0.007 mean/sd 0.013 0.009L 13 N 39 failure 0.127 arith-error 0.104 energy 0.0212 mean/sd 0.053 0.023L 13 N 1540 failure 0.187 arith-error 0.117 energy 0.0057 mean/sd 0.015 0.009L 17 N 942 failure 0.162 arith-error 0.089 energy 0.015 mean/sd 0.033 0.01L 17 N 793 failure 0.218 arith-error 0.106 energy 0.0035 mean/sd 0.007 0.006L 17 N 1475 failure 0.149 arith-error 0.066 energy 0.0091 mean/sd 0.015 0.015L 17 N 124 failure 0.102 arith-error 0.119 energy 0.0083 mean/sd 0.016 0.011L 17 N 1484 failure 0.129 arith-error 0.126 energy 0.005 mean/sd 0.009 0.007Weights remain unchanged.

Mechanical arithmetic checks: 3270 adjacent literal-number equalitiesCorrect responses with checked arithmetic error: 27 / 217Failed responses with checked arithmetic error: 82 / 295L 0 N 1405 mean/sd 13.373 6.971 top feature correlations [('digit_density', 0.318), ('repetition', 0.269), ('final_density', 0.132), ('latex_density', -0.126)]L 0 N 149 mean/sd 1.589 0.596 top feature correlations [('final_density', 0.329), ('repetition', 0.282), ('equality_density', -0.203), ('latex_density', -0.202)]L 0 N 1309 mean/sd 0.479 0.24 top feature correlations [('digit_density', 0.561), ('let_density', -0.144), ('arithmetic_error_count', 0.121), ('final_density', -0.094)]L 0 N 2032 mean/sd 0.169 0.193 top feature correlations [('digit_density', 0.4), ('final_density', -0.27), ('equality_density', 0.166), ('arithmetic_progress', -0.157)]L 0 N 761 mean/sd 0.321 0.277 top feature correlations [('digit_density', 0.59), ('arithmetic_error_count', 0.196), ('latex_density', -0.153), ('let_density', -0.122)]L 0 N 1479 mean/sd 0.165 0.201 top feature correlations [('digit_density', 0.487), ('identity_fraction', 0.177), ('arithmetic_error_count', 0.171), ('final_density', -0.121)]L 1 N 483 mean/sd 0.195 0.114 top feature correlations [('digit_density', 0.664), ('equality_density', 0.192), ('let_density', -0.157), ('arithmetic_error_count', 0.144)]L 1 N 1899 mean/sd 0.222 0.253 top feature correlations [('digit_density', 0.635), ('latex_density', -0.484), ('equality_density', 0.217), ('final_density', 0.141)]L 1 N 553 mean/sd 0.19 0.149 top feature correlations [('digit_density', 0.643), ('arithmetic_progress', -0.139), ('therefore_density', -0.133), ('final_density', -0.129)]L 1 N 421 mean/sd 0.198 0.107 top feature correlations [('digit_density', 0.42), ('equality_density', 0.226), ('latex_density', 0.171), ('arithmetic_error_count', 0.1)]L 1 N 1851 mean/sd 0.132 0.085 top feature correlations [('digit_density', 0.369), ('final_density', 0.316), ('equality_density', 0.134), ('therefore_density', -0.126)]L 1 N 1066 mean/sd 0.053 0.06 top feature correlations [('final_density', 0.442), ('arithmetic_error_count', 0.169), ('identity_fraction', 0.152), ('let_density', -0.109)]L 5 N 1111 mean/sd 0.004 0.018 top feature correlations [('final_density', 0.522), ('equality_density', -0.486), ('latex_density', -0.197), ('repetition', 0.119)]L 5 N 1244 mean/sd 0.052 0.046 top feature correlations [('digit_density', 0.492), ('final_density', -0.254), ('latex_density', 0.181), ('arithmetic_error_count', 0.136)]L 5 N 970 mean/sd 0.037 0.015 top feature correlations [('digit_density', 0.63), ('final_density', -0.23), ('equality_density', 0.167), ('therefore_density', -0.161)]L 5 N 207 mean/sd 0.014 0.013 top feature correlations [('final_density', 0.451), ('digit_density', 0.395), ('latex_density', -0.336), ('equality_density', -0.171)]L 5 N 473 mean/sd 0.022 0.01 top feature correlations [('final_density', 0.345), ('equality_density', -0.236), ('arithmetic_error', -0.141), ('arithmetic_progress', 0.097)]L 5 N 1493 mean/sd 0.013 0.014 top feature correlations [('equality_density', -0.522), ('final_density', 0.502), ('latex_density', -0.264), ('arithmetic_error_count', 0.092)]L 13 N 1226 mean/sd 0.028 0.011 top feature correlations [('digit_density', 0.343), ('equality_density', 0.149), ('arithmetic_progress', -0.128), ('final_density', -0.127)]L 13 N 231 mean/sd 0.035 0.016 top feature correlations [('digit_density', 0.607), ('equality_density', 0.268), ('final_density', -0.221), ('identity_fraction', 0.149)]L 13 N 1881 mean/sd 0.023 0.009 top feature correlations [('digit_density', 0.427), ('equality_density', 0.329), ('final_density', -0.179), ('arithmetic_progress', -0.17)]L 13 N 570 mean/sd 0.033 0.012 top feature correlations [('digit_density', 0.423), ('final_density', -0.304), ('identity_fraction', 0.248), ('latex_density', 0.152)]L 13 N 39 mean/sd 0.053 0.023 top feature correlations [('digit_density', 0.397), ('final_density', -0.38), ('arithmetic_error_count', 0.21), ('latex_density', 0.195)]L 13 N 1059 mean/sd 0.033 0.019 top feature correlations [('equality_density', 0.538), ('digit_density', 0.504), ('final_density', -0.242), ('latex_density', 0.235)]L 17 N 1451 mean/sd 0.183 0.06 top feature correlations [('digit_density', 0.375), ('equality_density', 0.272), ('identity_fraction', 0.264), ('repetition', 0.233)]L 17 N 653 mean/sd 0.037 0.009 top feature correlations [('digit_density', 0.289), ('equality_density', 0.259), ('final_density', -0.22), ('repetition', 0.154)]L 17 N 547 mean/sd 0.083 0.051 top feature correlations [('final_density', 0.375), ('latex_density', -0.373), ('digit_density', 0.275), ('equality_density', 0.264)]L 17 N 942 mean/sd 0.033 0.01 top feature correlations [('final_density', -0.491), ('digit_density', 0.464), ('equality_density', 0.259), ('therefore_density', -0.147)]L 17 N 211 mean/sd 0.067 0.044 top feature correlations [('final_density', 0.341), ('latex_density', -0.294), ('equality_density', -0.208), ('digit_density', -0.19)]L 17 N 1475 mean/sd 0.015 0.015 top feature correlations [('digit_density', 0.184), ('let_density', -0.167), ('identity_fraction', 0.113), ('final_density', -0.105)]Stable failure + arithmetic-error candidates:L 0 N 1028 failure 0.11 arith-error 0.154 energy 0.1002 mean/sd 0.106 0.126L 0 N 2032 failure 0.14 arith-error 0.092 energy 0.1355 mean/sd 0.169 0.193L 0 N 761 failure 0.114 arith-error 0.075 energy 0.2207 mean/sd 0.321 0.277L 0 N 1479 failure 0.113 arith-error 0.063 energy 0.1453 mean/sd 0.165 0.201L 0 N 845 failure 0.111 arith-error 0.066 energy 0.2212 mean/sd 0.251 0.262L 0 N 1450 failure 0.128 arith-error 0.082 energy 0.0428 mean/sd 0.023 0.064L 0 N 1013 failure 0.109 arith-error 0.08 energy 0.0683 mean/sd 0.047 0.116L 13 N 1881 failure 0.168 arith-error 0.117 energy 0.0101 mean/sd 0.023 0.009L 17 N 1554 failure 0.135 arith-error 0.165 energy 0.007 mean/sd 0.013 0.009L 13 N 39 failure 0.127 arith-error 0.104 energy 0.0212 mean/sd 0.053 0.023L 13 N 1540 failure 0.187 arith-error 0.117 energy 0.0057 mean/sd 0.015 0.009L 17 N 942 failure 0.162 arith-error 0.089 energy 0.015 mean/sd 0.033 0.01L 17 N 793 failure 0.218 arith-error 0.106 energy 0.0035 mean/sd 0.007 0.006L 17 N 1475 failure 0.149 arith-error 0.066 energy 0.0091 mean/sd 0.015 0.015L 17 N 124 failure 0.102 arith-error 0.119 energy 0.0083 mean/sd 0.016 0.011L 17 N 1484 failure 0.129 arith-error 0.126 energy 0.005 mean/sd 0.009 0.007Weights remain unchanged.

Mechanical checks found an invalid numeric equality in 82 of 295 failed DEV responses, versus 27 of 217 correct ones. However, several prominent early-layer candidates correlate more strongly with digit density than with arithmetic errors, so suppressing them could damage number processing rather than repair it. I’ll exclude that shortcut by controlling for numeric density and common formatting as well as length. The next screen will favor later-layer components associated with both failure and invalid arithmetic after those controls. This gives the intervention a narrower prediction: fewer incorrect transformations, with improved final-answer accuracy.

python

# Statistical residualization only: this does not train or run the model.control_names = [    "digit_density", "latex_density", "equality_density",    "final_density", "let_density", "therefore_density"]C = np.column_stack(    [loglen] + [Fc[:, feature_names.index(k)] for k in control_names])Q, _ = np.linalg.qr(C, mode="reduced")def remove_controls(x, mask=None):    if mask is None:        return x - Q @ (Q.T @ x)    c = C[mask]    q, _ = np.linalg.qr(c, mode="reduced")    z = x[mask]    return z - q @ (q.T @ z)
f_adj = remove_controls(failure)a_adj = remove_controls(Fc[:, feature_names.index("arithmetic_error")])p_adj = remove_controls(Fc[:, feature_names.index("arithmetic_progress")])i_adj = remove_controls(Fc[:, feature_names.index("identity_fraction")])r_adj = remove_controls(repeat)controlled_screen = []
for layer in range(18):    Xc = within_problem(np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64))    Xa = remove_controls(Xc)    normx = np.sqrt(np.sum(Xa * Xa, axis=0) + 1e-20)    def correlations(y):        return y @ Xa / (np.linalg.norm(y) * normx + 1e-20)    cf, ca, cp, ci, cr = [correlations(y) for y in [f_adj,a_adj,p_adj,i_adj,r_adj]]    ch = []    for half in [0,1]:        mask = groups_dev % 2 == half        xx = remove_controls(Xc, mask)        yy = remove_controls(failure, mask)        ch.append(yy @ xx / (            np.linalg.norm(yy) * np.sqrt(np.sum(xx*xx, axis=0) + 1e-20)        ))    prior = {s["neuron"]:s for s in neuron_screen if s["layer"] == layer}    for j in range(2048):        controlled_screen.append({            **prior[j],            "adjusted_failure": float(cf[j]),            "adjusted_arithmetic_error": float(ca[j]),            "adjusted_progress": float(cp[j]),            "adjusted_identity": float(ci[j]),            "adjusted_repeat": float(cr[j]),            "adjusted_half0": float(ch[0][j]),            "adjusted_half1": float(ch[1][j]),        })
controlled_candidates = [    s for s in controlled_screen    if s["layer"] >= 6    and s["mean"] > 0    and s["adjusted_failure"] > .10    and min(s["adjusted_half0"], s["adjusted_half1"]) > .045    and s["adjusted_arithmetic_error"] > .04]controlled_candidates.sort(    key=lambda s: (        min(s["adjusted_half0"], s["adjusted_half1"])        * math.sqrt(max(0, s["adjusted_arithmetic_error"]))    ), reverse=True)print("Late-layer candidates after surface-form controls:", len(controlled_candidates))for s in controlled_candidates[:24]:    print({        k: round(s[k], 3) if isinstance(s[k], float) else s[k]        for k in [            "layer","neuron","adjusted_failure","adjusted_arithmetic_error",            "adjusted_half0","adjusted_half1","adjusted_progress",            "adjusted_identity","energy"        ]    })
print("Top adjusted failure correlations by layer:")for layer in range(18):    ss = [s for s in controlled_screen if s["layer"] == layer]    s = max(ss, key=lambda s:s["adjusted_failure"])    print(layer, s["neuron"], round(s["adjusted_failure"],3),          "halves", round(s["adjusted_half0"],3), round(s["adjusted_half1"],3),          "arith", round(s["adjusted_arithmetic_error"],3))
with open("/work/controlled_neuron_screen.json", "w") as f:    json.dump(controlled_screen, f)print("No edit yet.")

# Statistical residualization only: this does not train or run the model.control_names = [    "digit_density", "latex_density", "equality_density",    "final_density", "let_density", "therefore_density"]C = np.column_stack(    [loglen] + [Fc[:, feature_names.index(k)] for k in control_names])Q, _ = np.linalg.qr(C, mode="reduced")def remove_controls(x, mask=None):    if mask is None:        return x - Q @ (Q.T @ x)    c = C[mask]    q, _ = np.linalg.qr(c, mode="reduced")    z = x[mask]    return z - q @ (q.T @ z)
f_adj = remove_controls(failure)a_adj = remove_controls(Fc[:, feature_names.index("arithmetic_error")])p_adj = remove_controls(Fc[:, feature_names.index("arithmetic_progress")])i_adj = remove_controls(Fc[:, feature_names.index("identity_fraction")])r_adj = remove_controls(repeat)controlled_screen = []
for layer in range(18):    Xc = within_problem(np.asarray(mlp_mean[dev_indices, layer, :], dtype=np.float64))    Xa = remove_controls(Xc)    normx = np.sqrt(np.sum(Xa * Xa, axis=0) + 1e-20)    def correlations(y):        return y @ Xa / (np.linalg.norm(y) * normx + 1e-20)    cf, ca, cp, ci, cr = [correlations(y) for y in [f_adj,a_adj,p_adj,i_adj,r_adj]]    ch = []    for half in [0,1]:        mask = groups_dev % 2 == half        xx = remove_controls(Xc, mask)        yy = remove_controls(failure, mask)        ch.append(yy @ xx / (            np.linalg.norm(yy) * np.sqrt(np.sum(xx*xx, axis=0) + 1e-20)        ))    prior = {s["neuron"]:s for s in neuron_screen if s["layer"] == layer}    for j in range(2048):        controlled_screen.append({            **prior[j],            "adjusted_failure": float(cf[j]),            "adjusted_arithmetic_error": float(ca[j]),            "adjusted_progress": float(cp[j]),            "adjusted_identity": float(ci[j]),            "adjusted_repeat": float(cr[j]),            "adjusted_half0": float(ch[0][j]),            "adjusted_half1": float(ch[1][j]),        })
controlled_candidates = [    s for s in controlled_screen    if s["layer"] >= 6    and s["mean"] > 0    and s["adjusted_failure"] > .10    and min(s["adjusted_half0"], s["adjusted_half1"]) > .045    and s["adjusted_arithmetic_error"] > .04]controlled_candidates.sort(    key=lambda s: (        min(s["adjusted_half0"], s["adjusted_half1"])        * math.sqrt(max(0, s["adjusted_arithmetic_error"]))    ), reverse=True)print("Late-layer candidates after surface-form controls:", len(controlled_candidates))for s in controlled_candidates[:24]:    print({        k: round(s[k], 3) if isinstance(s[k], float) else s[k]        for k in [            "layer","neuron","adjusted_failure","adjusted_arithmetic_error",            "adjusted_half0","adjusted_half1","adjusted_progress",            "adjusted_identity","energy"        ]    })
print("Top adjusted failure correlations by layer:")for layer in range(18):    ss = [s for s in controlled_screen if s["layer"] == layer]    s = max(ss, key=lambda s:s["adjusted_failure"])    print(layer, s["neuron"], round(s["adjusted_failure"],3),          "halves", round(s["adjusted_half0"],3), round(s["adjusted_half1"],3),          "arith", round(s["adjusted_arithmetic_error"],3))
with open("/work/controlled_neuron_screen.json", "w") as f:    json.dump(controlled_screen, f)print("No edit yet.")

OUTPUT of Python run 9 of at most 300:

Late-layer candidates after surface-form controls: 166{'layer': 17, 'neuron': 793, 'adjusted_failure': 0.208, 'adjusted_arithmetic_error': 0.117, 'adjusted_half0': 0.224, 'adjusted_half1': 0.213, 'adjusted_progress': -0.063, 'adjusted_identity': -0.087, 'energy': 0.004}{'layer': 16, 'neuron': 128, 'adjusted_failure': 0.149, 'adjusted_arithmetic_error': 0.173, 'adjusted_half0': 0.155, 'adjusted_half1': 0.153, 'adjusted_progress': -0.177, 'adjusted_identity': 0.065, 'energy': 0.006}{'layer': 11, 'neuron': 587, 'adjusted_failure': 0.172, 'adjusted_arithmetic_error': 0.135, 'adjusted_half0': 0.155, 'adjusted_half1': 0.182, 'adjusted_progress': -0.138, 'adjusted_identity': 0.14, 'energy': 0.036}{'layer': 14, 'neuron': 11, 'adjusted_failure': 0.157, 'adjusted_arithmetic_error': 0.128, 'adjusted_half0': 0.156, 'adjusted_half1': 0.174, 'adjusted_progress': -0.077, 'adjusted_identity': -0.024, 'energy': 0.002}{'layer': 13, 'neuron': 1881, 'adjusted_failure': 0.177, 'adjusted_arithmetic_error': 0.14, 'adjusted_half0': 0.187, 'adjusted_half1': 0.148, 'adjusted_progress': -0.127, 'adjusted_identity': 0.124, 'energy': 0.01}{'layer': 15, 'neuron': 1036, 'adjusted_failure': 0.142, 'adjusted_arithmetic_error': 0.129, 'adjusted_half0': 0.174, 'adjusted_half1': 0.148, 'adjusted_progress': -0.072, 'adjusted_identity': 0.093, 'energy': 0.007}{'layer': 12, 'neuron': 1797, 'adjusted_failure': 0.147, 'adjusted_arithmetic_error': 0.148, 'adjusted_half0': 0.136, 'adjusted_half1': 0.143, 'adjusted_progress': 0.014, 'adjusted_identity': -0.054, 'energy': 0.011}{'layer': 14, 'neuron': 1157, 'adjusted_failure': 0.137, 'adjusted_arithmetic_error': 0.193, 'adjusted_half0': 0.112, 'adjusted_half1': 0.159, 'adjusted_progress': -0.209, 'adjusted_identity': -0.018, 'energy': 0.004}{'layer': 13, 'neuron': 1540, 'adjusted_failure': 0.176, 'adjusted_arithmetic_error': 0.158, 'adjusted_half0': 0.211, 'adjusted_half1': 0.124, 'adjusted_progress': -0.075, 'adjusted_identity': -0.075, 'energy': 0.006}{'layer': 6, 'neuron': 1157, 'adjusted_failure': 0.136, 'adjusted_arithmetic_error': 0.125, 'adjusted_half0': 0.133, 'adjusted_half1': 0.135, 'adjusted_progress': -0.038, 'adjusted_identity': -0.018, 'energy': 0.012}{'layer': 17, 'neuron': 942, 'adjusted_failure': 0.175, 'adjusted_arithmetic_error': 0.097, 'adjusted_half0': 0.15, 'adjusted_half1': 0.202, 'adjusted_progress': -0.015, 'adjusted_identity': -0.138, 'energy': 0.015}{'layer': 13, 'neuron': 1098, 'adjusted_failure': 0.156, 'adjusted_arithmetic_error': 0.101, 'adjusted_half0': 0.194, 'adjusted_half1': 0.148, 'adjusted_progress': -0.06, 'adjusted_identity': -0.055, 'energy': 0.004}{'layer': 9, 'neuron': 1493, 'adjusted_failure': 0.15, 'adjusted_arithmetic_error': 0.12, 'adjusted_half0': 0.187, 'adjusted_half1': 0.135, 'adjusted_progress': -0.056, 'adjusted_identity': -0.066, 'energy': 0.005}{'layer': 17, 'neuron': 1554, 'adjusted_failure': 0.151, 'adjusted_arithmetic_error': 0.156, 'adjusted_half0': 0.203, 'adjusted_half1': 0.116, 'adjusted_progress': -0.141, 'adjusted_identity': 0.033, 'energy': 0.007}{'layer': 17, 'neuron': 1378, 'adjusted_failure': 0.115, 'adjusted_arithmetic_error': 0.152, 'adjusted_half0': 0.112, 'adjusted_half1': 0.132, 'adjusted_progress': -0.058, 'adjusted_identity': 0.084, 'energy': 0.006}{'layer': 16, 'neuron': 1315, 'adjusted_failure': 0.172, 'adjusted_arithmetic_error': 0.137, 'adjusted_half0': 0.118, 'adjusted_half1': 0.21, 'adjusted_progress': -0.003, 'adjusted_identity': -0.074, 'energy': 0.012}{'layer': 11, 'neuron': 1551, 'adjusted_failure': 0.122, 'adjusted_arithmetic_error': 0.129, 'adjusted_half0': 0.135, 'adjusted_half1': 0.121, 'adjusted_progress': -0.031, 'adjusted_identity': -0.2, 'energy': 0.007}{'layer': 8, 'neuron': 1777, 'adjusted_failure': 0.165, 'adjusted_arithmetic_error': 0.122, 'adjusted_half0': 0.12, 'adjusted_half1': 0.217, 'adjusted_progress': -0.067, 'adjusted_identity': -0.016, 'energy': 0.004}{'layer': 16, 'neuron': 1766, 'adjusted_failure': 0.19, 'adjusted_arithmetic_error': 0.091, 'adjusted_half0': 0.138, 'adjusted_half1': 0.242, 'adjusted_progress': -0.166, 'adjusted_identity': 0.014, 'energy': 0.004}{'layer': 9, 'neuron': 580, 'adjusted_failure': 0.142, 'adjusted_arithmetic_error': 0.119, 'adjusted_half0': 0.12, 'adjusted_half1': 0.139, 'adjusted_progress': -0.146, 'adjusted_identity': 0.04, 'energy': 0.021}{'layer': 8, 'neuron': 1185, 'adjusted_failure': 0.145, 'adjusted_arithmetic_error': 0.11, 'adjusted_half0': 0.123, 'adjusted_half1': 0.213, 'adjusted_progress': -0.047, 'adjusted_identity': 0.01, 'energy': 0.088}{'layer': 10, 'neuron': 1798, 'adjusted_failure': 0.139, 'adjusted_arithmetic_error': 0.091, 'adjusted_half0': 0.157, 'adjusted_half1': 0.135, 'adjusted_progress': -0.026, 'adjusted_identity': -0.116, 'energy': 0.005}{'layer': 17, 'neuron': 75, 'adjusted_failure': 0.115, 'adjusted_arithmetic_error': 0.122, 'adjusted_half0': 0.118, 'adjusted_half1': 0.114, 'adjusted_progress': -0.05, 'adjusted_identity': -0.083, 'energy': 0.018}{'layer': 17, 'neuron': 1484, 'adjusted_failure': 0.146, 'adjusted_arithmetic_error': 0.147, 'adjusted_half0': 0.101, 'adjusted_half1': 0.211, 'adjusted_progress': -0.154, 'adjusted_identity': 0.025, 'energy': 0.005}Top adjusted failure correlations by layer:0 1869 0.194 halves 0.257 0.139 arith 0.0211 694 0.18 halves 0.152 0.227 arith -0.0732 1616 0.145 halves 0.203 0.052 arith -0.0083 1628 0.158 halves 0.169 0.139 arith 0.0614 193 0.193 halves 0.244 0.111 arith 0.0465 1111 0.151 halves 0.128 0.159 arith -0.0046 1850 0.163 halves 0.171 0.166 arith 0.0337 796 0.171 halves 0.145 0.228 arith 0.0118 1751 0.188 halves 0.172 0.213 arith 0.0349 175 0.164 halves 0.126 0.243 arith 0.07710 779 0.154 halves 0.232 0.076 arith 0.02711 401 0.21 halves 0.203 0.227 arith 0.11112 467 0.164 halves 0.133 0.185 arith -0.02513 1226 0.216 halves 0.188 0.265 arith 0.00414 1202 0.228 halves 0.13 0.315 arith 0.07815 1839 0.17 halves 0.139 0.205 arith 0.08416 250 0.191 halves 0.123 0.257 arith 0.09717 793 0.208 halves 0.224 0.213 arith 0.117No edit yet.

Late-layer candidates after surface-form controls: 166{'layer': 17, 'neuron': 793, 'adjusted_failure': 0.208, 'adjusted_arithmetic_error': 0.117, 'adjusted_half0': 0.224, 'adjusted_half1': 0.213, 'adjusted_progress': -0.063, 'adjusted_identity': -0.087, 'energy': 0.004}{'layer': 16, 'neuron': 128, 'adjusted_failure': 0.149, 'adjusted_arithmetic_error': 0.173, 'adjusted_half0': 0.155, 'adjusted_half1': 0.153, 'adjusted_progress': -0.177, 'adjusted_identity': 0.065, 'energy': 0.006}{'layer': 11, 'neuron': 587, 'adjusted_failure': 0.172, 'adjusted_arithmetic_error': 0.135, 'adjusted_half0': 0.155, 'adjusted_half1': 0.182, 'adjusted_progress': -0.138, 'adjusted_identity': 0.14, 'energy': 0.036}{'layer': 14, 'neuron': 11, 'adjusted_failure': 0.157, 'adjusted_arithmetic_error': 0.128, 'adjusted_half0': 0.156, 'adjusted_half1': 0.174, 'adjusted_progress': -0.077, 'adjusted_identity': -0.024, 'energy': 0.002}{'layer': 13, 'neuron': 1881, 'adjusted_failure': 0.177, 'adjusted_arithmetic_error': 0.14, 'adjusted_half0': 0.187, 'adjusted_half1': 0.148, 'adjusted_progress': -0.127, 'adjusted_identity': 0.124, 'energy': 0.01}{'layer': 15, 'neuron': 1036, 'adjusted_failure': 0.142, 'adjusted_arithmetic_error': 0.129, 'adjusted_half0': 0.174, 'adjusted_half1': 0.148, 'adjusted_progress': -0.072, 'adjusted_identity': 0.093, 'energy': 0.007}{'layer': 12, 'neuron': 1797, 'adjusted_failure': 0.147, 'adjusted_arithmetic_error': 0.148, 'adjusted_half0': 0.136, 'adjusted_half1': 0.143, 'adjusted_progress': 0.014, 'adjusted_identity': -0.054, 'energy': 0.011}{'layer': 14, 'neuron': 1157, 'adjusted_failure': 0.137, 'adjusted_arithmetic_error': 0.193, 'adjusted_half0': 0.112, 'adjusted_half1': 0.159, 'adjusted_progress': -0.209, 'adjusted_identity': -0.018, 'energy': 0.004}{'layer': 13, 'neuron': 1540, 'adjusted_failure': 0.176, 'adjusted_arithmetic_error': 0.158, 'adjusted_half0': 0.211, 'adjusted_half1': 0.124, 'adjusted_progress': -0.075, 'adjusted_identity': -0.075, 'energy': 0.006}{'layer': 6, 'neuron': 1157, 'adjusted_failure': 0.136, 'adjusted_arithmetic_error': 0.125, 'adjusted_half0': 0.133, 'adjusted_half1': 0.135, 'adjusted_progress': -0.038, 'adjusted_identity': -0.018, 'energy': 0.012}{'layer': 17, 'neuron': 942, 'adjusted_failure': 0.175, 'adjusted_arithmetic_error': 0.097, 'adjusted_half0': 0.15, 'adjusted_half1': 0.202, 'adjusted_progress': -0.015, 'adjusted_identity': -0.138, 'energy': 0.015}{'layer': 13, 'neuron': 1098, 'adjusted_failure': 0.156, 'adjusted_arithmetic_error': 0.101, 'adjusted_half0': 0.194, 'adjusted_half1': 0.148, 'adjusted_progress': -0.06, 'adjusted_identity': -0.055, 'energy': 0.004}{'layer': 9, 'neuron': 1493, 'adjusted_failure': 0.15, 'adjusted_arithmetic_error': 0.12, 'adjusted_half0': 0.187, 'adjusted_half1': 0.135, 'adjusted_progress': -0.056, 'adjusted_identity': -0.066, 'energy': 0.005}{'layer': 17, 'neuron': 1554, 'adjusted_failure': 0.151, 'adjusted_arithmetic_error': 0.156, 'adjusted_half0': 0.203, 'adjusted_half1': 0.116, 'adjusted_progress': -0.141, 'adjusted_identity': 0.033, 'energy': 0.007}{'layer': 17, 'neuron': 1378, 'adjusted_failure': 0.115, 'adjusted_arithmetic_error': 0.152, 'adjusted_half0': 0.112, 'adjusted_half1': 0.132, 'adjusted_progress': -0.058, 'adjusted_identity': 0.084, 'energy': 0.006}{'layer': 16, 'neuron': 1315, 'adjusted_failure': 0.172, 'adjusted_arithmetic_error': 0.137, 'adjusted_half0': 0.118, 'adjusted_half1': 0.21, 'adjusted_progress': -0.003, 'adjusted_identity': -0.074, 'energy': 0.012}{'layer': 11, 'neuron': 1551, 'adjusted_failure': 0.122, 'adjusted_arithmetic_error': 0.129, 'adjusted_half0': 0.135, 'adjusted_half1': 0.121, 'adjusted_progress': -0.031, 'adjusted_identity': -0.2, 'energy': 0.007}{'layer': 8, 'neuron': 1777, 'adjusted_failure': 0.165, 'adjusted_arithmetic_error': 0.122, 'adjusted_half0': 0.12, 'adjusted_half1': 0.217, 'adjusted_progress': -0.067, 'adjusted_identity': -0.016, 'energy': 0.004}{'layer': 16, 'neuron': 1766, 'adjusted_failure': 0.19, 'adjusted_arithmetic_error': 0.091, 'adjusted_half0': 0.138, 'adjusted_half1': 0.242, 'adjusted_progress': -0.166, 'adjusted_identity': 0.014, 'energy': 0.004}{'layer': 9, 'neuron': 580, 'adjusted_failure': 0.142, 'adjusted_arithmetic_error': 0.119, 'adjusted_half0': 0.12, 'adjusted_half1': 0.139, 'adjusted_progress': -0.146, 'adjusted_identity': 0.04, 'energy': 0.021}{'layer': 8, 'neuron': 1185, 'adjusted_failure': 0.145, 'adjusted_arithmetic_error': 0.11, 'adjusted_half0': 0.123, 'adjusted_half1': 0.213, 'adjusted_progress': -0.047, 'adjusted_identity': 0.01, 'energy': 0.088}{'layer': 10, 'neuron': 1798, 'adjusted_failure': 0.139, 'adjusted_arithmetic_error': 0.091, 'adjusted_half0': 0.157, 'adjusted_half1': 0.135, 'adjusted_progress': -0.026, 'adjusted_identity': -0.116, 'energy': 0.005}{'layer': 17, 'neuron': 75, 'adjusted_failure': 0.115, 'adjusted_arithmetic_error': 0.122, 'adjusted_half0': 0.118, 'adjusted_half1': 0.114, 'adjusted_progress': -0.05, 'adjusted_identity': -0.083, 'energy': 0.018}{'layer': 17, 'neuron': 1484, 'adjusted_failure': 0.146, 'adjusted_arithmetic_error': 0.147, 'adjusted_half0': 0.101, 'adjusted_half1': 0.211, 'adjusted_progress': -0.154, 'adjusted_identity': 0.025, 'energy': 0.005}Top adjusted failure correlations by layer:0 1869 0.194 halves 0.257 0.139 arith 0.0211 694 0.18 halves 0.152 0.227 arith -0.0732 1616 0.145 halves 0.203 0.052 arith -0.0083 1628 0.158 halves 0.169 0.139 arith 0.0614 193 0.193 halves 0.244 0.111 arith 0.0465 1111 0.151 halves 0.128 0.159 arith -0.0046 1850 0.163 halves 0.171 0.166 arith 0.0337 796 0.171 halves 0.145 0.228 arith 0.0118 1751 0.188 halves 0.172 0.213 arith 0.0349 175 0.164 halves 0.126 0.243 arith 0.07710 779 0.154 halves 0.232 0.076 arith 0.02711 401 0.21 halves 0.203 0.227 arith 0.11112 467 0.164 halves 0.133 0.185 arith -0.02513 1226 0.216 halves 0.188 0.265 arith 0.00414 1202 0.228 halves 0.13 0.315 arith 0.07815 1839 0.17 halves 0.139 0.205 arith 0.08416 250 0.191 halves 0.123 0.257 arith 0.09717 793 0.208 halves 0.224 0.213 arith 0.117No edit yet.

After controlling for surface features, 166 later-layer channels remain associated with both failure and arithmetic errors, with the failure association present in both DEV halves. I’ll further screen their output directions to avoid suppressing channels that appear to oppose the observed failure-associated layer update. From that screen, I’ll fix a sparse set of at most 64 neurons and halve only their down_proj columns. The next two DEV passes will compare half suppression with full removal of the same set. This tests a tentative hypothesis about reinforcement of invalid transformations; improved accuracy and fewer checked arithmetic errors would support it, while degradation would argue against it.

python

torch.set_grad_enabled(False)
# Geometry of existing weights and recorded activations, not a forward simulation.for layer in range(6,18):    delta = (        np.asarray(hidden_mean[dev_indices, layer+1, :], dtype=np.float64)        - np.asarray(hidden_mean[dev_indices, layer, :], dtype=np.float64)    )    delta_adj = remove_controls(within_problem(delta))    direction = f_adj @ delta_adj / (f_adj @ f_adj)    D = load_original(f"model.layers.{layer}.mlp.down_proj.weight").numpy().astype(np.float64)    gamma = 1 + load_original(        f"model.layers.{layer}.post_feedforward_layernorm.weight"    ).numpy().astype(np.float64)    columns = gamma[:,None] * D    align = direction @ columns / (        np.linalg.norm(direction) * np.linalg.norm(columns, axis=0) + 1e-20    )    for s in controlled_candidates:        if s["layer"] == layer:            s["failure_update_alignment"] = float(align[s["neuron"]])
reinforcing = [    s for s in controlled_candidates if s["failure_update_alignment"] > 0]selected_components = reinforcing[:64]assert len(selected_components) >= 16selected_by_layer = collections.defaultdict(list)for s in selected_components:    selected_by_layer[s["layer"]].append(s["neuron"])selected_by_layer = {l: sorted(js) for l,js in sorted(selected_by_layer.items())}
selection_manifest = {    "hypothesis": "Sparse late MLP outputs reinforce invalid numerical transformations.",    "selection": (        "Within-DEV-problem correlations, controlling log length and six surface "        "features; positive-mean neurons in layers 6-17; adjusted failure>.10; "        "both DEV-half failure correlations>.045; adjusted arithmetic-error>.04; "        "positive output alignment with the observed failure-associated block update. "        "Rank by min half correlation times sqrt arithmetic-error correlation; top64."    ),    "neurons": {str(l):js for l,js in selected_by_layer.items()},    "evidence": selected_components,    "planned_strengths": [0.5,1.0],    "primary_outcome": "paired final-answer accuracy",    "secondary_outcomes": [        "responses containing mechanically checked false numeric equalities",        "arithmetic-check coverage", "failure types", "repetition"    ],}with open("/work/candidate_manifest.json", "w") as f:    json.dump(selection_manifest, f, indent=2)
def apply_candidate(strength):    summaries = []    for layer, js in selected_by_layer.items():        name = f"model.layers.{layer}.mlp.down_proj.weight"        original = load_original(name)        new = original.clone()        new[:, js] = original[:, js] * (1-strength)        save_edit(name, new)        summaries.append({            "layer": layer, "neurons": len(js),            "relative_frobenius_change": float(torch.linalg.vector_norm(new-original)                                               / torch.linalg.vector_norm(original))        })    return summaries
strength = 0.5edit_summary = apply_candidate(strength)with open("/work/notes.md", "a") as f:    f.write(        "\n## Candidate fixed before causal tests\n"        "- Selection and complete neuron evidence: candidate_manifest.json.\n"        "- Sparse down_proj column suppression only; no embeddings, output matrix, "        "norms, attention, gate_proj or up_proj edited.\n"        f"- Exact selected columns by layer: {json.dumps(selected_by_layer)}.\n"        "- Hypothesis: these outputs reinforce invalid numerical transformations. "        "Association and output geometry alone are not causal proof.\n"        "\n## Pass 3: paired DEV, half suppression\n"        "- Exact edit: for each selected layer/column above, "        "down_proj[:,j] = 0.5 * original[:,j]; all other values unchanged.\n"        "- Problems: DEV_ids.json; 32 problems x 32 samples/model = 1024/model.\n"        "- Both models, temperature/top-k/top-p fixed by evaluator; max_tokens=[REDACTED]        "- Accuracy is primary; arithmetic errors and coverage are secondary.\n"        "- Next planned dose: full removal of exactly the same columns.\n"    )
import shutilshutil.copytree("/work/edited", "/work/candidate_half", dirs_exist_ok=True)print("Selected neurons:", sum(map(len,selected_by_layer.values())))print("Selected columns by layer:", json.dumps(selected_by_layer))print("Geometry-screen survivors:", len(reinforcing))print("Per-tensor changes:", edit_summary)print("Edited tensor count:", len(edited()))print("Half-strength candidate backed up; HOLDOUT untouched.")

torch.set_grad_enabled(False)
# Geometry of existing weights and recorded activations, not a forward simulation.for layer in range(6,18):    delta = (        np.asarray(hidden_mean[dev_indices, layer+1, :], dtype=np.float64)        - np.asarray(hidden_mean[dev_indices, layer, :], dtype=np.float64)    )    delta_adj = remove_controls(within_problem(delta))    direction = f_adj @ delta_adj / (f_adj @ f_adj)    D = load_original(f"model.layers.{layer}.mlp.down_proj.weight").numpy().astype(np.float64)    gamma = 1 + load_original(        f"model.layers.{layer}.post_feedforward_layernorm.weight"    ).numpy().astype(np.float64)    columns = gamma[:,None] * D    align = direction @ columns / (        np.linalg.norm(direction) * np.linalg.norm(columns, axis=0) + 1e-20    )    for s in controlled_candidates:        if s["layer"] == layer:            s["failure_update_alignment"] = float(align[s["neuron"]])
reinforcing = [    s for s in controlled_candidates if s["failure_update_alignment"] > 0]selected_components = reinforcing[:64]assert len(selected_components) >= 16selected_by_layer = collections.defaultdict(list)for s in selected_components:    selected_by_layer[s["layer"]].append(s["neuron"])selected_by_layer = {l: sorted(js) for l,js in sorted(selected_by_layer.items())}
selection_manifest = {    "hypothesis": "Sparse late MLP outputs reinforce invalid numerical transformations.",    "selection": (        "Within-DEV-problem correlations, controlling log length and six surface "        "features; positive-mean neurons in layers 6-17; adjusted failure>.10; "        "both DEV-half failure correlations>.045; adjusted arithmetic-error>.04; "        "positive output alignment with the observed failure-associated block update. "        "Rank by min half correlation times sqrt arithmetic-error correlation; top64."    ),    "neurons": {str(l):js for l,js in selected_by_layer.items()},    "evidence": selected_components,    "planned_strengths": [0.5,1.0],    "primary_outcome": "paired final-answer accuracy",    "secondary_outcomes": [        "responses containing mechanically checked false numeric equalities",        "arithmetic-check coverage", "failure types", "repetition"    ],}with open("/work/candidate_manifest.json", "w") as f:    json.dump(selection_manifest, f, indent=2)
def apply_candidate(strength):    summaries = []    for layer, js in selected_by_layer.items():        name = f"model.layers.{layer}.mlp.down_proj.weight"        original = load_original(name)        new = original.clone()        new[:, js] = original[:, js] * (1-strength)        save_edit(name, new)        summaries.append({            "layer": layer, "neurons": len(js),            "relative_frobenius_change": float(torch.linalg.vector_norm(new-original)                                               / torch.linalg.vector_norm(original))        })    return summaries
strength = 0.5edit_summary = apply_candidate(strength)with open("/work/notes.md", "a") as f:    f.write(        "\n## Candidate fixed before causal tests\n"        "- Selection and complete neuron evidence: candidate_manifest.json.\n"        "- Sparse down_proj column suppression only; no embeddings, output matrix, "        "norms, attention, gate_proj or up_proj edited.\n"        f"- Exact selected columns by layer: {json.dumps(selected_by_layer)}.\n"        "- Hypothesis: these outputs reinforce invalid numerical transformations. "        "Association and output geometry alone are not causal proof.\n"        "\n## Pass 3: paired DEV, half suppression\n"        "- Exact edit: for each selected layer/column above, "        "down_proj[:,j] = 0.5 * original[:,j]; all other values unchanged.\n"        "- Problems: DEV_ids.json; 32 problems x 32 samples/model = 1024/model.\n"        "- Both models, temperature/top-k/top-p fixed by evaluator; max_tokens=[REDACTED]        "- Accuracy is primary; arithmetic errors and coverage are secondary.\n"        "- Next planned dose: full removal of exactly the same columns.\n"    )
import shutilshutil.copytree("/work/edited", "/work/candidate_half", dirs_exist_ok=True)print("Selected neurons:", sum(map(len,selected_by_layer.values())))print("Selected columns by layer:", json.dumps(selected_by_layer))print("Geometry-screen survivors:", len(reinforcing))print("Per-tensor changes:", edit_summary)print("Edited tensor count:", len(edited()))print("Half-strength candidate backed up; HOLDOUT untouched.")

OUTPUT of Python run 10 of at most 300:

Selected neurons: 64Selected columns by layer: {"6": [640, 678, 1157], "7": [637, 1621], "8": [477, 792, 1777, 1865], "9": [884, 1493], "10": [1621, 1798], "11": [1, 587, 672, 1551, 1890], "12": [1123, 1184, 1278, 1797, 1894], "13": [39, 759, 1059, 1260, 1540, 1881], "14": [11, 23, 238, 640, 1157, 1202, 1497, 1935], "15": [661, 968, 1304, 1507, 1818], "16": [128, 255, 322, 513, 663, 1315, 1486, 1548, 1598, 1649, 1876, 2004], "17": [124, 942, 1115, 1222, 1326, 1475, 1484, 1554, 1688, 1741]}Geometry-screen survivors: 106Per-tensor changes: [{'layer': 6, 'neurons': 3, 'relative_frobenius_change': 0.020754922181367874}, {'layer': 7, 'neurons': 2, 'relative_frobenius_change': 0.014555721543729305}, {'layer': 8, 'neurons': 4, 'relative_frobenius_change': 0.02329275943338871}, {'layer': 9, 'neurons': 2, 'relative_frobenius_change': 0.014009480364620686}, {'layer': 10, 'neurons': 2, 'relative_frobenius_change': 0.012839410454034805}, {'layer': 11, 'neurons': 5, 'relative_frobenius_change': 0.02441495656967163}, {'layer': 12, 'neurons': 5, 'relative_frobenius_change': 0.026036622002720833}, {'layer': 13, 'neurons': 6, 'relative_frobenius_change': 0.028796641156077385}, {'layer': 14, 'neurons': 8, 'relative_frobenius_change': 0.0321677103638649}, {'layer': 15, 'neurons': 5, 'relative_frobenius_change': 0.025061622262001038}, {'layer': 16, 'neurons': 12, 'relative_frobenius_change': 0.038654133677482605}, {'layer': 17, 'neurons': 10, 'relative_frobenius_change': 0.037476081401109695}]Edited tensor count: 12Half-strength candidate backed up; HOLDOUT untouched.

Selected neurons: 64Selected columns by layer: {"6": [640, 678, 1157], "7": [637, 1621], "8": [477, 792, 1777, 1865], "9": [884, 1493], "10": [1621, 1798], "11": [1, 587, 672, 1551, 1890], "12": [1123, 1184, 1278, 1797, 1894], "13": [39, 759, 1059, 1260, 1540, 1881], "14": [11, 23, 238, 640, 1157, 1202, 1497, 1935], "15": [661, 968, 1304, 1507, 1818], "16": [128, 255, 322, 513, 663, 1315, 1486, 1548, 1598, 1649, 1876, 2004], "17": [124, 942, 1115, 1222, 1326, 1475, 1484, 1554, 1688, 1741]}Geometry-screen survivors: 106Per-tensor changes: [{'layer': 6, 'neurons': 3, 'relative_frobenius_change': 0.020754922181367874}, {'layer': 7, 'neurons': 2, 'relative_frobenius_change': 0.014555721543729305}, {'layer': 8, 'neurons': 4, 'relative_frobenius_change': 0.02329275943338871}, {'layer': 9, 'neurons': 2, 'relative_frobenius_change': 0.014009480364620686}, {'layer': 10, 'neurons': 2, 'relative_frobenius_change': 0.012839410454034805}, {'layer': 11, 'neurons': 5, 'relative_frobenius_change': 0.02441495656967163}, {'layer': 12, 'neurons': 5, 'relative_frobenius_change': 0.026036622002720833}, {'layer': 13, 'neurons': 6, 'relative_frobenius_change': 0.028796641156077385}, {'layer': 14, 'neurons': 8, 'relative_frobenius_change': 0.0321677103638649}, {'layer': 15, 'neurons': 5, 'relative_frobenius_change': 0.025061622262001038}, {'layer': 16, 'neurons': 12, 'relative_frobenius_change': 0.038654133677482605}, {'layer': 17, 'neurons': 10, 'relative_frobenius_change': 0.037476081401109695}]Edited tensor count: 12Half-strength candidate backed up; HOLDOUT untouched.

The first edit is saved: 64 neuron-output columns across layers 6–17 are halved, with all other weight values unchanged. The selected columns and selection evidence are recorded, and the candidate is backed up. Per-tensor changes are about 1.3–3.9% in Frobenius norm, so this is not a negligible perturbation. I’ll now compare it with the original on all 32 DEV problems, using 1,024 answers per model and the full token limit. Final-answer accuracy will decide whether it helps; arithmetic checks will test the proposed mechanism.

forward

{"type":"generate","model":"both","problems":["math_train_counting_and_probability_606","math_train_prealgebra_593","math_train_algebra_1707","math_train_prealgebra_55","math_train_prealgebra_940","math_train_algebra_1114","math_train_intermediate_algebra_633","math_train_prealgebra_207","math_train_prealgebra_502","math_train_precalculus_220","math_train_algebra_498","math_train_algebra_636","math_train_counting_and_probability_148","math_train_prealgebra_318","math_train_prealgebra_780","math_train_algebra_1497","math_train_algebra_182","math_train_intermediate_algebra_643","math_train_intermediate_algebra_933","math_train_number_theory_540","math_train_number_theory_696","math_train_prealgebra_774","math_train_algebra_1461","math_train_algebra_1523","math_train_algebra_731","math_train_algebra_958","math_train_geometry_158","math_train_intermediate_algebra_80","math_train_prealgebra_202","math_train_prealgebra_590","math_train_prealgebra_839","math_train_algebra_1423"],"n":32,"max_tokens":8192}

{"type":"generate","model":"both","problems":["math_train_counting_and_probability_606","math_train_prealgebra_593","math_train_algebra_1707","math_train_prealgebra_55","math_train_prealgebra_940","math_train_algebra_1114","math_train_intermediate_algebra_633","math_train_prealgebra_207","math_train_prealgebra_502","math_train_precalculus_220","math_train_algebra_498","math_train_algebra_636","math_train_counting_and_probability_148","math_train_prealgebra_318","math_train_prealgebra_780","math_train_algebra_1497","math_train_algebra_182","math_train_intermediate_algebra_643","math_train_intermediate_algebra_933","math_train_number_theory_540","math_train_number_theory_696","math_train_prealgebra_774","math_train_algebra_1461","math_train_algebra_1523","math_train_algebra_731","math_train_algebra_958","math_train_geometry_158","math_train_intermediate_algebra_80","math_train_prealgebra_202","math_train_prealgebra_590","math_train_prealgebra_839","math_train_algebra_1423"],"n":32,"max_tokens":8192}

Forward pass 3 of 5 done (generate); results in /work/gen_3_original.jsonl and /work/gen_3_edited.jsonl. Summary:

{ "ok": true, "type": "generate", "model": "both", "files": {  "original": "/work/gen_3_original.jsonl",  "edited": "/work/gen_3_edited.jsonl" }, "activations": null, "original": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.39453125,  "accuracy_by_source": {   "math": 0.3945  },  "mean_tokens": 1327,  "cut_share": 0.0791,  "failures": {   "wrong_answer": 276,   "no_answer_finished": 279,   "cut_at_max_tokens": 65  } }, "edited": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.3896484375,  "accuracy_by_source": {   "math": 0.3896  },  "mean_tokens": 1138,  "cut_share": 0.0566,  "failures": {   "wrong_answer": 310,   "no_answer_finished": 273,   "cut_at_max_tokens": 42  } }, "paired": {  "items": 32,  "accuracy_difference": -0.0049,  "standard_error": 0.0157,  "samples_wrong_to_right": 143,  "samples_right_to_wrong": 148 }, "s": 643.2}

{ "ok": true, "type": "generate", "model": "both", "files": {  "original": "/work/gen_3_original.jsonl",  "edited": "/work/gen_3_edited.jsonl" }, "activations": null, "original": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.39453125,  "accuracy_by_source": {   "math": 0.3945  },  "mean_tokens": 1327,  "cut_share": 0.0791,  "failures": {   "wrong_answer": 276,   "no_answer_finished": 279,   "cut_at_max_tokens": 65  } }, "edited": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.3896484375,  "accuracy_by_source": {   "math": 0.3896  },  "mean_tokens": 1138,  "cut_share": 0.0566,  "failures": {   "wrong_answer": 310,   "no_answer_finished": 273,   "cut_at_max_tokens": 42  } }, "paired": {  "items": 32,  "accuracy_difference": -0.0049,  "standard_error": 0.0157,  "samples_wrong_to_right": 143,  "samples_right_to_wrong": 148 }, "s": 643.2}

Forward passes left: 2. Edits used in this pass: model.layers.10.mlp.down_proj.weight, model.layers.11.mlp.down_proj.weight, model.layers.12.mlp.down_proj.weight, model.layers.13.mlp.down_proj.weight, model.layers.14.mlp.down_proj.weight, model.layers.15.mlp.down_proj.weight, model.layers.16.mlp.down_proj.weight, model.layers.17.mlp.down_proj.weight, model.layers.6.mlp.down_proj.weight, model.layers.7.mlp.down_proj.weight, model.layers.8.mlp.down_proj.weight, model.layers.9.mlp.down_proj.weight (edit hash bddc69e0d6).

Half suppression did not improve DEV accuracy: the paired difference was −0.49 percentage points, with a reported standard error of 1.57 points. Responses became shorter and cutoffs decreased, but those changes are not evidence of better mathematics. I’ll check whether mechanically verified arithmetic errors changed, then test full removal of exactly the same 64 columns as planned. If stronger suppression reduces truncation but not errors or accuracy, the proposed repair mechanism will remain unsupported. The holdout is still untouched.

python

def load_generation_file(path):    with open(path) as f:        grouped = [json.loads(line) for line in f]    flat = []    for group in grouped:        for j, s in enumerate(group["samples"]):            flat.append({                **s, "problem_id": group["id"], "sample_index": j,                "reference": group["answer"],            })    return flat
def mechanism_summary(rr):    eq_lists = [numeric_equalities(r["text"]) for r in rr]    checked = np.array([len(e)>0 for e in eq_lists])    bad = np.array([any(not v[0] for v in e) for e in eq_lists])    n_bad = sum(sum(not v[0] for v in e) for e in eq_lists)    n_valid_progress = sum(sum(v[0] and not v[1] for v in e) for e in eq_lists)    n_identity = sum(sum(v[1] for v in e) for e in eq_lists)    result = {        "answers": len(rr),        "correct": sum(r["correct"] for r in rr),        "checked_response_share": float(checked.mean()),        "response_with_checked_error_share": float(bad.mean()),        "error_share_among_checked_responses": float(bad.sum()/max(1,checked.sum())),        "checked_false_equalities": int(n_bad),        "checked_valid_progress_equalities": int(n_valid_progress),        "checked_identity_equalities": int(n_identity),        "median_tokens": float(np.median([r["tokens"] for r in rr])),        "cut_responses": sum(r["cut"] for r in rr),    }    return result, bad, checked
dev_half_original = load_generation_file("/work/gen_3_original.jsonl")dev_half_edited = load_generation_file("/work/gen_3_edited.jsonl")assert [    (r["problem_id"],r["sample_index"]) for r in dev_half_original] == [(r["problem_id"],r["sample_index"]) for r in dev_half_edited]
half_mechanisms = {}for label, rr in [("original",dev_half_original), ("half_suppression",dev_half_edited)]:    summary, bad, checked = mechanism_summary(rr)    half_mechanisms[label] = summary    print(label, summary)with open("/work/dev_half_mechanisms.json", "w") as f:    json.dump(half_mechanisms, f, indent=2)
for lo, hi in [(0,256),(256,512),(512,1024),(1024,2048),(2048,9000)]:    row = {"token_range": [lo,hi]}    for label, rr in [("original",dev_half_original), ("edited",dev_half_edited)]:        subset = [r for r in rr if lo <= r["tokens"] < hi]        if subset:            s,_,_ = mechanism_summary(subset)            row[label] = {                "n":len(subset),                "accuracy":round(s["correct"]/s["answers"],3),                "checked_error_share":round(s["response_with_checked_error_share"],3)            }    print(row)
strength = 1.0full_summary = apply_candidate(strength)shutil.copytree("/work/edited", "/work/candidate_full", dirs_exist_ok=True)with open("/work/notes.md", "a") as f:    f.write(        "\n## Pass 3 results\n"        "- Original: 404/1024 (39.4531%); half suppression: 399/1024 (38.9648%).\n"        "- Paired difference: -0.49 percentage points; tool-reported SE 1.57 points.\n"        "- Wrong-to-right 143; right-to-wrong 148. No accuracy benefit demonstrated.\n"        "- Cut share fell from 7.91% to 5.66%; not treated as success.\n"        "- Arithmetic diagnostics: dev_half_mechanisms.json.\n"        "\n## Pass 4: paired DEV, full suppression\n"        "- Exact edit: same 64 columns in candidate_manifest.json, "        "down_proj[:,j] = 0; all other tensor values unchanged.\n"        "- Same 32 DEV problems, 32 samples/model = 1024/model, "        "max_tokens=[REDACTED] both original and edited.\n"        "- Half and full candidates are backed up separately. "        "Select by within-pass accuracy difference, not response length.\n"        "- HOLDOUT still untouched; freeze the better tested non-original "        "candidate before pass 5.\n"    )print("Full-removal edit saved:", len(edited()), "tensors.")print("Relative changes:", [    (s["layer"], round(s["relative_frobenius_change"],4)) for s in full_summary])

def load_generation_file(path):    with open(path) as f:        grouped = [json.loads(line) for line in f]    flat = []    for group in grouped:        for j, s in enumerate(group["samples"]):            flat.append({                **s, "problem_id": group["id"], "sample_index": j,                "reference": group["answer"],            })    return flat
def mechanism_summary(rr):    eq_lists = [numeric_equalities(r["text"]) for r in rr]    checked = np.array([len(e)>0 for e in eq_lists])    bad = np.array([any(not v[0] for v in e) for e in eq_lists])    n_bad = sum(sum(not v[0] for v in e) for e in eq_lists)    n_valid_progress = sum(sum(v[0] and not v[1] for v in e) for e in eq_lists)    n_identity = sum(sum(v[1] for v in e) for e in eq_lists)    result = {        "answers": len(rr),        "correct": sum(r["correct"] for r in rr),        "checked_response_share": float(checked.mean()),        "response_with_checked_error_share": float(bad.mean()),        "error_share_among_checked_responses": float(bad.sum()/max(1,checked.sum())),        "checked_false_equalities": int(n_bad),        "checked_valid_progress_equalities": int(n_valid_progress),        "checked_identity_equalities": int(n_identity),        "median_tokens": float(np.median([r["tokens"] for r in rr])),        "cut_responses": sum(r["cut"] for r in rr),    }    return result, bad, checked
dev_half_original = load_generation_file("/work/gen_3_original.jsonl")dev_half_edited = load_generation_file("/work/gen_3_edited.jsonl")assert [    (r["problem_id"],r["sample_index"]) for r in dev_half_original] == [(r["problem_id"],r["sample_index"]) for r in dev_half_edited]
half_mechanisms = {}for label, rr in [("original",dev_half_original), ("half_suppression",dev_half_edited)]:    summary, bad, checked = mechanism_summary(rr)    half_mechanisms[label] = summary    print(label, summary)with open("/work/dev_half_mechanisms.json", "w") as f:    json.dump(half_mechanisms, f, indent=2)
for lo, hi in [(0,256),(256,512),(512,1024),(1024,2048),(2048,9000)]:    row = {"token_range": [lo,hi]}    for label, rr in [("original",dev_half_original), ("edited",dev_half_edited)]:        subset = [r for r in rr if lo <= r["tokens"] < hi]        if subset:            s,_,_ = mechanism_summary(subset)            row[label] = {                "n":len(subset),                "accuracy":round(s["correct"]/s["answers"],3),                "checked_error_share":round(s["response_with_checked_error_share"],3)            }    print(row)
strength = 1.0full_summary = apply_candidate(strength)shutil.copytree("/work/edited", "/work/candidate_full", dirs_exist_ok=True)with open("/work/notes.md", "a") as f:    f.write(        "\n## Pass 3 results\n"        "- Original: 404/1024 (39.4531%); half suppression: 399/1024 (38.9648%).\n"        "- Paired difference: -0.49 percentage points; tool-reported SE 1.57 points.\n"        "- Wrong-to-right 143; right-to-wrong 148. No accuracy benefit demonstrated.\n"        "- Cut share fell from 7.91% to 5.66%; not treated as success.\n"        "- Arithmetic diagnostics: dev_half_mechanisms.json.\n"        "\n## Pass 4: paired DEV, full suppression\n"        "- Exact edit: same 64 columns in candidate_manifest.json, "        "down_proj[:,j] = 0; all other tensor values unchanged.\n"        "- Same 32 DEV problems, 32 samples/model = 1024/model, "        "max_tokens=[REDACTED] both original and edited.\n"        "- Half and full candidates are backed up separately. "        "Select by within-pass accuracy difference, not response length.\n"        "- HOLDOUT still untouched; freeze the better tested non-original "        "candidate before pass 5.\n"    )print("Full-removal edit saved:", len(edited()), "tensors.")print("Relative changes:", [    (s["layer"], round(s["relative_frobenius_change"],4)) for s in full_summary])

OUTPUT of Python run 11 of at most 300:

original {'answers': 1024, 'correct': 404, 'checked_response_share': 0.689453125, 'response_with_checked_error_share': 0.1904296875, 'error_share_among_checked_responses': 0.2762039660056657, 'checked_false_equalities': 573, 'checked_valid_progress_equalities': 3779, 'checked_identity_equalities': 1933, 'median_tokens': 539.0, 'cut_responses': 81}half_suppression {'answers': 1024, 'correct': 399, 'checked_response_share': 0.69921875, 'response_with_checked_error_share': 0.1845703125, 'error_share_among_checked_responses': 0.2639664804469274, 'checked_false_equalities': 598, 'checked_valid_progress_equalities': 2992, 'checked_identity_equalities': 1667, 'median_tokens': 509.5, 'cut_responses': 58}{'token_range': [0, 256], 'original': {'n': 235, 'accuracy': 0.472, 'checked_error_share': 0.106}, 'edited': {'n': 257, 'accuracy': 0.447, 'checked_error_share': 0.16}}{'token_range': [256, 512], 'original': {'n': 262, 'accuracy': 0.466, 'checked_error_share': 0.183}, 'edited': {'n': 258, 'accuracy': 0.434, 'checked_error_share': 0.167}}{'token_range': [512, 1024], 'original': {'n': 244, 'accuracy': 0.381, 'checked_error_share': 0.303}, 'edited': {'n': 254, 'accuracy': 0.386, 'checked_error_share': 0.252}}{'token_range': [1024, 2048], 'original': {'n': 150, 'accuracy': 0.293, 'checked_error_share': 0.173}, 'edited': {'n': 150, 'accuracy': 0.3, 'checked_error_share': 0.18}}{'token_range': [2048, 9000], 'original': {'n': 133, 'accuracy': 0.256, 'checked_error_share': 0.165}, 'edited': {'n': 105, 'accuracy': 0.276, 'checked_error_share': 0.133}}Full-removal edit saved: 12 tensors.Relative changes: [(6, 0.0415), (7, 0.0291), (8, 0.0466), (9, 0.028), (10, 0.0257), (11, 0.0488), (12, 0.0521), (13, 0.0576), (14, 0.0643), (15, 0.0501), (16, 0.0773), (17, 0.075)]

original {'answers': 1024, 'correct': 404, 'checked_response_share': 0.689453125, 'response_with_checked_error_share': 0.1904296875, 'error_share_among_checked_responses': 0.2762039660056657, 'checked_false_equalities': 573, 'checked_valid_progress_equalities': 3779, 'checked_identity_equalities': 1933, 'median_tokens': 539.0, 'cut_responses': 81}half_suppression {'answers': 1024, 'correct': 399, 'checked_response_share': 0.69921875, 'response_with_checked_error_share': 0.1845703125, 'error_share_among_checked_responses': 0.2639664804469274, 'checked_false_equalities': 598, 'checked_valid_progress_equalities': 2992, 'checked_identity_equalities': 1667, 'median_tokens': 509.5, 'cut_responses': 58}{'token_range': [0, 256], 'original': {'n': 235, 'accuracy': 0.472, 'checked_error_share': 0.106}, 'edited': {'n': 257, 'accuracy': 0.447, 'checked_error_share': 0.16}}{'token_range': [256, 512], 'original': {'n': 262, 'accuracy': 0.466, 'checked_error_share': 0.183}, 'edited': {'n': 258, 'accuracy': 0.434, 'checked_error_share': 0.167}}{'token_range': [512, 1024], 'original': {'n': 244, 'accuracy': 0.381, 'checked_error_share': 0.303}, 'edited': {'n': 254, 'accuracy': 0.386, 'checked_error_share': 0.252}}{'token_range': [1024, 2048], 'original': {'n': 150, 'accuracy': 0.293, 'checked_error_share': 0.173}, 'edited': {'n': 150, 'accuracy': 0.3, 'checked_error_share': 0.18}}{'token_range': [2048, 9000], 'original': {'n': 133, 'accuracy': 0.256, 'checked_error_share': 0.165}, 'edited': {'n': 105, 'accuracy': 0.276, 'checked_error_share': 0.133}}Full-removal edit saved: 12 tensors.Relative changes: [(6, 0.0415), (7, 0.0291), (8, 0.0466), (9, 0.028), (10, 0.0257), (11, 0.0488), (12, 0.0521), (13, 0.0576), (14, 0.0643), (15, 0.0501), (16, 0.0773), (17, 0.075)]

Half suppression changed the share of responses containing a checked arithmetic error only slightly, from 19.04% to 18.46%, with similar checking coverage. The total number of false equalities actually increased, so these diagnostics do not establish an arithmetic repair. Full removal of the same columns is now saved and documented. This stronger test will show whether the weak result reflects an insufficient dose or an unhelpful component selection. I’ll choose between the two tested edits by paired accuracy before opening HOLDOUT.

forward

{"type":"generate","model":"both","problems":["math_train_counting_and_probability_606","math_train_prealgebra_593","math_train_algebra_1707","math_train_prealgebra_55","math_train_prealgebra_940","math_train_algebra_1114","math_train_intermediate_algebra_633","math_train_prealgebra_207","math_train_prealgebra_502","math_train_precalculus_220","math_train_algebra_498","math_train_algebra_636","math_train_counting_and_probability_148","math_train_prealgebra_318","math_train_prealgebra_780","math_train_algebra_1497","math_train_algebra_182","math_train_intermediate_algebra_643","math_train_intermediate_algebra_933","math_train_number_theory_540","math_train_number_theory_696","math_train_prealgebra_774","math_train_algebra_1461","math_train_algebra_1523","math_train_algebra_731","math_train_algebra_958","math_train_geometry_158","math_train_intermediate_algebra_80","math_train_prealgebra_202","math_train_prealgebra_590","math_train_prealgebra_839","math_train_algebra_1423"],"n":32,"max_tokens":8192}

{"type":"generate","model":"both","problems":["math_train_counting_and_probability_606","math_train_prealgebra_593","math_train_algebra_1707","math_train_prealgebra_55","math_train_prealgebra_940","math_train_algebra_1114","math_train_intermediate_algebra_633","math_train_prealgebra_207","math_train_prealgebra_502","math_train_precalculus_220","math_train_algebra_498","math_train_algebra_636","math_train_counting_and_probability_148","math_train_prealgebra_318","math_train_prealgebra_780","math_train_algebra_1497","math_train_algebra_182","math_train_intermediate_algebra_643","math_train_intermediate_algebra_933","math_train_number_theory_540","math_train_number_theory_696","math_train_prealgebra_774","math_train_algebra_1461","math_train_algebra_1523","math_train_algebra_731","math_train_algebra_958","math_train_geometry_158","math_train_intermediate_algebra_80","math_train_prealgebra_202","math_train_prealgebra_590","math_train_prealgebra_839","math_train_algebra_1423"],"n":32,"max_tokens":8192}

Forward pass 4 of 5 done (generate); results in /work/gen_4_original.jsonl and /work/gen_4_edited.jsonl. Summary:

{ "ok": true, "type": "generate", "model": "both", "files": {  "original": "/work/gen_4_original.jsonl",  "edited": "/work/gen_4_edited.jsonl" }, "activations": null, "original": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.3955078125,  "accuracy_by_source": {   "math": 0.3955  },  "mean_tokens": 1380,  "cut_share": 0.082,  "failures": {   "wrong_answer": 259,   "no_answer_finished": 303,   "cut_at_max_tokens": 57  } }, "edited": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.349609375,  "accuracy_by_source": {   "math": 0.3496  },  "mean_tokens": 1058,  "cut_share": 0.0508,  "failures": {   "wrong_answer": 359,   "no_answer_finished": 263,   "cut_at_max_tokens": 44  } }, "paired": {  "items": 32,  "accuracy_difference": -0.0459,  "standard_error": 0.017,  "samples_wrong_to_right": 155,  "samples_right_to_wrong": 202 }, "s": 372.0}

{ "ok": true, "type": "generate", "model": "both", "files": {  "original": "/work/gen_4_original.jsonl",  "edited": "/work/gen_4_edited.jsonl" }, "activations": null, "original": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.3955078125,  "accuracy_by_source": {   "math": 0.3955  },  "mean_tokens": 1380,  "cut_share": 0.082,  "failures": {   "wrong_answer": 259,   "no_answer_finished": 303,   "cut_at_max_tokens": 57  } }, "edited": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.349609375,  "accuracy_by_source": {   "math": 0.3496  },  "mean_tokens": 1058,  "cut_share": 0.0508,  "failures": {   "wrong_answer": 359,   "no_answer_finished": 263,   "cut_at_max_tokens": 44  } }, "paired": {  "items": 32,  "accuracy_difference": -0.0459,  "standard_error": 0.017,  "samples_wrong_to_right": 155,  "samples_right_to_wrong": 202 }, "s": 372.0}

Forward passes left: 1. Edits used in this pass: model.layers.10.mlp.down_proj.weight, model.layers.11.mlp.down_proj.weight, model.layers.12.mlp.down_proj.weight, model.layers.13.mlp.down_proj.weight, model.layers.14.mlp.down_proj.weight, model.layers.15.mlp.down_proj.weight, model.layers.16.mlp.down_proj.weight, model.layers.17.mlp.down_proj.weight, model.layers.6.mlp.down_proj.weight, model.layers.7.mlp.down_proj.weight, model.layers.8.mlp.down_proj.weight, model.layers.9.mlp.down_proj.weight (edit hash 0fc06385ac).

Full removal reduced DEV accuracy by 4.59 percentage points, with a reported standard error of 1.70 points, despite further reducing cutoffs. That argues against treating these channels as a purely harmful arithmetic circuit: they appear to carry useful computation too. I’ll restore the half-strength edit—not the original model—because it was the better of the two tested candidates. Its DEV result still does not demonstrate an improvement. I’ll now freeze that exact candidate and use the reserved holdout only for confirmation, with no further tuning.

python

dev_full_original = load_generation_file("/work/gen_4_original.jsonl")dev_full_edited = load_generation_file("/work/gen_4_edited.jsonl")full_mechanisms = {}for label, rr in [("original",dev_full_original), ("full_suppression",dev_full_edited)]:    summary, _, _ = mechanism_summary(rr)    full_mechanisms[label] = summary    print(label, summary)with open("/work/dev_full_mechanisms.json", "w") as f:    json.dump(full_mechanisms, f, indent=2)
# Select solely from DEV, before any holdout generations.chosen_strength = 0.5apply_candidate(chosen_strength)
import hashlibfrozen_hashes = {}for layer, js in selected_by_layer.items():    name = f"model.layers.{layer}.mlp.down_proj.weight"    original = load_original(name)    current = load(name)    mask = torch.ones(original.shape[1], dtype=torch.bool)    mask[js] = False    assert current.shape == original.shape    assert torch.equal(current[:, mask], original[:, mask])    assert torch.equal(current[:, js], 0.5 * original[:, js])    frozen_hashes[name] = hashlib.sha256(        current.contiguous().numpy().tobytes()    ).hexdigest()
shutil.copytree("/work/edited", "/work/best_1", dirs_exist_ok=True)frozen_manifest = {    "strength": chosen_strength,    "columns": {str(l):js for l,js in selected_by_layer.items()},    "tensor_sha256_float32": frozen_hashes,    "chosen_using": "DEV paired accuracy only",    "dev_half_difference_pp": -0.48828125,    "dev_half_reported_se_pp": 1.57,    "dev_full_difference_pp": -4.58984375,    "dev_full_reported_se_pp": 1.70,    "holdout_ids_file": "/work/HOLDOUT_ids.json",    "frozen_before_holdout": True,}with open("/work/frozen_candidate.json", "w") as f:    json.dump(frozen_manifest, f, indent=2)with open("/work/notes.md", "a") as f:    f.write(        "\n## Pass 4 results and candidate selection\n"        "- Original: 405/1024 (39.5508%); full suppression: 358/1024 (34.9609%).\n"        "- Paired difference: -4.59 points; tool-reported SE 1.70 points.\n"        "- Wrong-to-right 155; right-to-wrong 202. Full removal is harmful on DEV.\n"        "- Strong suppression hypothesis is not supported. Reduced truncation "        "does not imply improved mathematical accuracy.\n"        "- Best tested non-original candidate: half suppression, selected on DEV "        "only. It has no demonstrated DEV accuracy benefit.\n"        "\n## Candidate frozen before HOLDOUT\n"        "- Exact edit: down_proj[:,j] = 0.5 * original[:,j] for the same 64 columns "        "in candidate_manifest.json; all other values unchanged.\n"        "- Verified bitwise unchanged unselected columns; tensor hashes saved "        "in frozen_candidate.json. Backup: /work/best_1/.\n"        "- No further candidate selection or tuning using HOLDOUT.\n"        "\n## Pass 5: frozen HOLDOUT confirmation\n"        "- Problems: HOLDOUT_ids.json, fixed before baseline; 128 MATH problems.\n"        "- Both models, 8 samples/problem = 1024 answers/model, max_tokens=[REDACTED]        "- Report the paired accuracy difference and its uncertainty honestly, "        "including a negative or inconclusive result.\n"    )print("Frozen strength:", chosen_strength)print("Verified edited tensors:", len(frozen_hashes))print("Edited scalar weights:", 640 * sum(map(len, selected_by_layer.values())))print("HOLDOUT IDs:")print(json.dumps(holdout_ids))

dev_full_original = load_generation_file("/work/gen_4_original.jsonl")dev_full_edited = load_generation_file("/work/gen_4_edited.jsonl")full_mechanisms = {}for label, rr in [("original",dev_full_original), ("full_suppression",dev_full_edited)]:    summary, _, _ = mechanism_summary(rr)    full_mechanisms[label] = summary    print(label, summary)with open("/work/dev_full_mechanisms.json", "w") as f:    json.dump(full_mechanisms, f, indent=2)
# Select solely from DEV, before any holdout generations.chosen_strength = 0.5apply_candidate(chosen_strength)
import hashlibfrozen_hashes = {}for layer, js in selected_by_layer.items():    name = f"model.layers.{layer}.mlp.down_proj.weight"    original = load_original(name)    current = load(name)    mask = torch.ones(original.shape[1], dtype=torch.bool)    mask[js] = False    assert current.shape == original.shape    assert torch.equal(current[:, mask], original[:, mask])    assert torch.equal(current[:, js], 0.5 * original[:, js])    frozen_hashes[name] = hashlib.sha256(        current.contiguous().numpy().tobytes()    ).hexdigest()
shutil.copytree("/work/edited", "/work/best_1", dirs_exist_ok=True)frozen_manifest = {    "strength": chosen_strength,    "columns": {str(l):js for l,js in selected_by_layer.items()},    "tensor_sha256_float32": frozen_hashes,    "chosen_using": "DEV paired accuracy only",    "dev_half_difference_pp": -0.48828125,    "dev_half_reported_se_pp": 1.57,    "dev_full_difference_pp": -4.58984375,    "dev_full_reported_se_pp": 1.70,    "holdout_ids_file": "/work/HOLDOUT_ids.json",    "frozen_before_holdout": True,}with open("/work/frozen_candidate.json", "w") as f:    json.dump(frozen_manifest, f, indent=2)with open("/work/notes.md", "a") as f:    f.write(        "\n## Pass 4 results and candidate selection\n"        "- Original: 405/1024 (39.5508%); full suppression: 358/1024 (34.9609%).\n"        "- Paired difference: -4.59 points; tool-reported SE 1.70 points.\n"        "- Wrong-to-right 155; right-to-wrong 202. Full removal is harmful on DEV.\n"        "- Strong suppression hypothesis is not supported. Reduced truncation "        "does not imply improved mathematical accuracy.\n"        "- Best tested non-original candidate: half suppression, selected on DEV "        "only. It has no demonstrated DEV accuracy benefit.\n"        "\n## Candidate frozen before HOLDOUT\n"        "- Exact edit: down_proj[:,j] = 0.5 * original[:,j] for the same 64 columns "        "in candidate_manifest.json; all other values unchanged.\n"        "- Verified bitwise unchanged unselected columns; tensor hashes saved "        "in frozen_candidate.json. Backup: /work/best_1/.\n"        "- No further candidate selection or tuning using HOLDOUT.\n"        "\n## Pass 5: frozen HOLDOUT confirmation\n"        "- Problems: HOLDOUT_ids.json, fixed before baseline; 128 MATH problems.\n"        "- Both models, 8 samples/problem = 1024 answers/model, max_tokens=[REDACTED]        "- Report the paired accuracy difference and its uncertainty honestly, "        "including a negative or inconclusive result.\n"    )print("Frozen strength:", chosen_strength)print("Verified edited tensors:", len(frozen_hashes))print("Edited scalar weights:", 640 * sum(map(len, selected_by_layer.values())))print("HOLDOUT IDs:")print(json.dumps(holdout_ids))

OUTPUT of Python run 12 of at most 300:

original {'answers': 1024, 'correct': 405, 'checked_response_share': 0.724609375, 'response_with_checked_error_share': 0.205078125, 'error_share_among_checked_responses': 0.2830188679245283, 'checked_false_equalities': 709, 'checked_valid_progress_equalities': 3966, 'checked_identity_equalities': 1851, 'median_tokens': 560.5, 'cut_responses': 84}full_suppression {'answers': 1024, 'correct': 358, 'checked_response_share': 0.69921875, 'response_with_checked_error_share': 0.20703125, 'error_share_among_checked_responses': 0.29608938547486036, 'checked_false_equalities': 570, 'checked_valid_progress_equalities': 2683, 'checked_identity_equalities': 1613, 'median_tokens': 433.0, 'cut_responses': 52}Frozen strength: 0.5Verified edited tensors: 12Edited scalar weights: 40960HOLDOUT IDs:["math_train_intermediate_algebra_849", "math_train_prealgebra_89", "math_train_algebra_212", "math_train_precalculus_527", "math_train_precalculus_188", "math_train_algebra_1237", "math_train_algebra_265", "math_train_algebra_1141", "math_train_prealgebra_301", "math_train_algebra_1719", "math_train_precalculus_199", "math_train_algebra_715", "math_train_algebra_853", "math_train_number_theory_525", "math_train_prealgebra_553", "math_train_algebra_950", "math_train_intermediate_algebra_358", "math_train_algebra_1187", "math_train_number_theory_376", "math_train_intermediate_algebra_32", "math_train_number_theory_444", "math_train_algebra_863", "math_train_algebra_1311", "math_train_number_theory_220", "math_train_number_theory_320", "math_train_number_theory_399", "math_train_algebra_1328", "math_train_algebra_634", "math_train_counting_and_probability_481", "math_train_number_theory_512", "math_train_algebra_778", "math_train_intermediate_algebra_462", "math_train_intermediate_algebra_591", "math_train_prealgebra_277", "math_train_number_theory_437", "math_train_algebra_961", "math_train_intermediate_algebra_1165", "math_train_number_theory_375", "math_train_algebra_944", "math_train_algebra_13", "math_train_prealgebra_50", "math_train_intermediate_algebra_178", "math_train_number_theory_742", "math_train_prealgebra_1012", "math_train_algebra_579", "math_train_precalculus_285", "math_train_algebra_935", "math_train_counting_and_probability_77", "math_train_algebra_107", "math_train_precalculus_223", "math_train_algebra_289", "math_train_prealgebra_790", "math_train_algebra_1363", "math_train_prealgebra_30", "math_train_algebra_1245", "math_train_prealgebra_809", "math_train_intermediate_algebra_714", "math_train_algebra_1577", "math_train_intermediate_algebra_1073", "math_train_intermediate_algebra_213", "math_train_algebra_441", "math_train_number_theory_866", "math_train_precalculus_603", "math_train_number_theory_119", "math_train_counting_and_probability_695", "math_train_geometry_829", "math_train_precalculus_219", "math_train_precalculus_16", "math_train_number_theory_441", "math_train_prealgebra_674", "math_train_algebra_835", "math_train_geometry_366", "math_train_intermediate_algebra_899", "math_train_geometry_778", "math_train_intermediate_algebra_227", "math_train_counting_and_probability_733", "math_train_prealgebra_881", "math_train_algebra_554", "math_train_number_theory_750", "math_train_intermediate_algebra_866", "math_train_intermediate_algebra_998", "math_train_counting_and_probability_602", "math_train_prealgebra_691", "math_train_counting_and_probability_559", "math_train_geometry_810", "math_train_prealgebra_1102", "math_train_algebra_202", "math_train_prealgebra_612", "math_train_counting_and_probability_657", "math_train_intermediate_algebra_423", "math_train_prealgebra_31", "math_train_precalculus_72", "math_train_counting_and_probability_570", "math_train_algebra_368", "math_train_counting_and_probability_270", "math_train_algebra_1518", "math_train_prealgebra_939", "math_train_intermediate_algebra_314", "math_train_intermediate_algebra_170", "math_train_counting_and_probability_604", "math_train_algebra_479", "math_train_number_theory_265", "math_train_intermediate_algebra_131", "math_train_intermediate_algebra_588", "math_train_counting_and_probability_448", "math_train_prealgebra_350", "math_train_geometry_741", "math_train_counting_and_probability_682", "math_train_algebra_1534", "math_train_counting_and_probability_344", "math_train_prealgebra_924", "math_train_prealgebra_101", "math_train_number_theory_339", "math_train_geometry_621", "math_train_intermediate_algebra_1056", "math_train_counting_and_probability_315", "math_train_number_theory_411", "math_train_precalculus_422", "math_train_prealgebra_1171", "math_train_number_theory_140", "math_train_number_theory_669", "math_train_counting_and_probability_546", "math_train_algebra_1594", "math_train_algebra_1554", "math_train_algebra_1253", "math_train_intermediate_algebra_716", "math_train_counting_and_probability_361", "math_train_algebra_436"]

original {'answers': 1024, 'correct': 405, 'checked_response_share': 0.724609375, 'response_with_checked_error_share': 0.205078125, 'error_share_among_checked_responses': 0.2830188679245283, 'checked_false_equalities': 709, 'checked_valid_progress_equalities': 3966, 'checked_identity_equalities': 1851, 'median_tokens': 560.5, 'cut_responses': 84}full_suppression {'answers': 1024, 'correct': 358, 'checked_response_share': 0.69921875, 'response_with_checked_error_share': 0.20703125, 'error_share_among_checked_responses': 0.29608938547486036, 'checked_false_equalities': 570, 'checked_valid_progress_equalities': 2683, 'checked_identity_equalities': 1613, 'median_tokens': 433.0, 'cut_responses': 52}Frozen strength: 0.5Verified edited tensors: 12Edited scalar weights: 40960HOLDOUT IDs:["math_train_intermediate_algebra_849", "math_train_prealgebra_89", "math_train_algebra_212", "math_train_precalculus_527", "math_train_precalculus_188", "math_train_algebra_1237", "math_train_algebra_265", "math_train_algebra_1141", "math_train_prealgebra_301", "math_train_algebra_1719", "math_train_precalculus_199", "math_train_algebra_715", "math_train_algebra_853", "math_train_number_theory_525", "math_train_prealgebra_553", "math_train_algebra_950", "math_train_intermediate_algebra_358", "math_train_algebra_1187", "math_train_number_theory_376", "math_train_intermediate_algebra_32", "math_train_number_theory_444", "math_train_algebra_863", "math_train_algebra_1311", "math_train_number_theory_220", "math_train_number_theory_320", "math_train_number_theory_399", "math_train_algebra_1328", "math_train_algebra_634", "math_train_counting_and_probability_481", "math_train_number_theory_512", "math_train_algebra_778", "math_train_intermediate_algebra_462", "math_train_intermediate_algebra_591", "math_train_prealgebra_277", "math_train_number_theory_437", "math_train_algebra_961", "math_train_intermediate_algebra_1165", "math_train_number_theory_375", "math_train_algebra_944", "math_train_algebra_13", "math_train_prealgebra_50", "math_train_intermediate_algebra_178", "math_train_number_theory_742", "math_train_prealgebra_1012", "math_train_algebra_579", "math_train_precalculus_285", "math_train_algebra_935", "math_train_counting_and_probability_77", "math_train_algebra_107", "math_train_precalculus_223", "math_train_algebra_289", "math_train_prealgebra_790", "math_train_algebra_1363", "math_train_prealgebra_30", "math_train_algebra_1245", "math_train_prealgebra_809", "math_train_intermediate_algebra_714", "math_train_algebra_1577", "math_train_intermediate_algebra_1073", "math_train_intermediate_algebra_213", "math_train_algebra_441", "math_train_number_theory_866", "math_train_precalculus_603", "math_train_number_theory_119", "math_train_counting_and_probability_695", "math_train_geometry_829", "math_train_precalculus_219", "math_train_precalculus_16", "math_train_number_theory_441", "math_train_prealgebra_674", "math_train_algebra_835", "math_train_geometry_366", "math_train_intermediate_algebra_899", "math_train_geometry_778", "math_train_intermediate_algebra_227", "math_train_counting_and_probability_733", "math_train_prealgebra_881", "math_train_algebra_554", "math_train_number_theory_750", "math_train_intermediate_algebra_866", "math_train_intermediate_algebra_998", "math_train_counting_and_probability_602", "math_train_prealgebra_691", "math_train_counting_and_probability_559", "math_train_geometry_810", "math_train_prealgebra_1102", "math_train_algebra_202", "math_train_prealgebra_612", "math_train_counting_and_probability_657", "math_train_intermediate_algebra_423", "math_train_prealgebra_31", "math_train_precalculus_72", "math_train_counting_and_probability_570", "math_train_algebra_368", "math_train_counting_and_probability_270", "math_train_algebra_1518", "math_train_prealgebra_939", "math_train_intermediate_algebra_314", "math_train_intermediate_algebra_170", "math_train_counting_and_probability_604", "math_train_algebra_479", "math_train_number_theory_265", "math_train_intermediate_algebra_131", "math_train_intermediate_algebra_588", "math_train_counting_and_probability_448", "math_train_prealgebra_350", "math_train_geometry_741", "math_train_counting_and_probability_682", "math_train_algebra_1534", "math_train_counting_and_probability_344", "math_train_prealgebra_924", "math_train_prealgebra_101", "math_train_number_theory_339", "math_train_geometry_621", "math_train_intermediate_algebra_1056", "math_train_counting_and_probability_315", "math_train_number_theory_411", "math_train_precalculus_422", "math_train_prealgebra_1171", "math_train_number_theory_140", "math_train_number_theory_669", "math_train_counting_and_probability_546", "math_train_algebra_1594", "math_train_algebra_1554", "math_train_algebra_1253", "math_train_intermediate_algebra_716", "math_train_counting_and_probability_361", "math_train_algebra_436"]

The half-strength candidate is frozen, backed up, and verified: exactly 40,960 weight values in 64 down_proj columns differ from the original. Full removal increased arithmetic-error incidence among checked responses and reduced valid arithmetic progress, reinforcing the decision not to use it. I’ll now run the final paired comparison on the 128 reserved MATH problems, with 1,024 answers per model. This is the first holdout evaluation, and its result will be reported without changing the candidate.

forward

{"type":"generate","model":"both","problems":["math_train_intermediate_algebra_849","math_train_prealgebra_89","math_train_algebra_212","math_train_precalculus_527","math_train_precalculus_188","math_train_algebra_1237","math_train_algebra_265","math_train_algebra_1141","math_train_prealgebra_301","math_train_algebra_1719","math_train_precalculus_199","math_train_algebra_715","math_train_algebra_853","math_train_number_theory_525","math_train_prealgebra_553","math_train_algebra_950","math_train_intermediate_algebra_358","math_train_algebra_1187","math_train_number_theory_376","math_train_intermediate_algebra_32","math_train_number_theory_444","math_train_algebra_863","math_train_algebra_1311","math_train_number_theory_220","math_train_number_theory_320","math_train_number_theory_399","math_train_algebra_1328","math_train_algebra_634","math_train_counting_and_probability_481","math_train_number_theory_512","math_train_algebra_778","math_train_intermediate_algebra_462","math_train_intermediate_algebra_591","math_train_prealgebra_277","math_train_number_theory_437","math_train_algebra_961","math_train_intermediate_algebra_1165","math_train_number_theory_375","math_train_algebra_944","math_train_algebra_13","math_train_prealgebra_50","math_train_intermediate_algebra_178","math_train_number_theory_742","math_train_prealgebra_1012","math_train_algebra_579","math_train_precalculus_285","math_train_algebra_935","math_train_counting_and_probability_77","math_train_algebra_107","math_train_precalculus_223","math_train_algebra_289","math_train_prealgebra_790","math_train_algebra_1363","math_train_prealgebra_30","math_train_algebra_1245","math_train_prealgebra_809","math_train_intermediate_algebra_714","math_train_algebra_1577","math_train_intermediate_algebra_1073","math_train_intermediate_algebra_213","math_train_algebra_441","math_train_number_theory_866","math_train_precalculus_603","math_train_number_theory_119","math_train_counting_and_probability_695","math_train_geometry_829","math_train_precalculus_219","math_train_precalculus_16","math_train_number_theory_441","math_train_prealgebra_674","math_train_algebra_835","math_train_geometry_366","math_train_intermediate_algebra_899","math_train_geometry_778","math_train_intermediate_algebra_227","math_train_counting_and_probability_733","math_train_prealgebra_881","math_train_algebra_554","math_train_number_theory_750","math_train_intermediate_algebra_866","math_train_intermediate_algebra_998","math_train_counting_and_probability_602","math_train_prealgebra_691","math_train_counting_and_probability_559","math_train_geometry_810","math_train_prealgebra_1102","math_train_algebra_202","math_train_prealgebra_612","math_train_counting_and_probability_657","math_train_intermediate_algebra_423","math_train_prealgebra_31","math_train_precalculus_72","math_train_counting_and_probability_570","math_train_algebra_368","math_train_counting_and_probability_270","math_train_algebra_1518","math_train_prealgebra_939","math_train_intermediate_algebra_314","math_train_intermediate_algebra_170","math_train_counting_and_probability_604","math_train_algebra_479","math_train_number_theory_265","math_train_intermediate_algebra_131","math_train_intermediate_algebra_588","math_train_counting_and_probability_448","math_train_prealgebra_350","math_train_geometry_741","math_train_counting_and_probability_682","math_train_algebra_1534","math_train_counting_and_probability_344","math_train_prealgebra_924","math_train_prealgebra_101","math_train_number_theory_339","math_train_geometry_621","math_train_intermediate_algebra_1056","math_train_counting_and_probability_315","math_train_number_theory_411","math_train_precalculus_422","math_train_prealgebra_1171","math_train_number_theory_140","math_train_number_theory_669","math_train_counting_and_probability_546","math_train_algebra_1594","math_train_algebra_1554","math_train_algebra_1253","math_train_intermediate_algebra_716","math_train_counting_and_probability_361","math_train_algebra_436"],"n":8,"max_tokens":8192}

{"type":"generate","model":"both","problems":["math_train_intermediate_algebra_849","math_train_prealgebra_89","math_train_algebra_212","math_train_precalculus_527","math_train_precalculus_188","math_train_algebra_1237","math_train_algebra_265","math_train_algebra_1141","math_train_prealgebra_301","math_train_algebra_1719","math_train_precalculus_199","math_train_algebra_715","math_train_algebra_853","math_train_number_theory_525","math_train_prealgebra_553","math_train_algebra_950","math_train_intermediate_algebra_358","math_train_algebra_1187","math_train_number_theory_376","math_train_intermediate_algebra_32","math_train_number_theory_444","math_train_algebra_863","math_train_algebra_1311","math_train_number_theory_220","math_train_number_theory_320","math_train_number_theory_399","math_train_algebra_1328","math_train_algebra_634","math_train_counting_and_probability_481","math_train_number_theory_512","math_train_algebra_778","math_train_intermediate_algebra_462","math_train_intermediate_algebra_591","math_train_prealgebra_277","math_train_number_theory_437","math_train_algebra_961","math_train_intermediate_algebra_1165","math_train_number_theory_375","math_train_algebra_944","math_train_algebra_13","math_train_prealgebra_50","math_train_intermediate_algebra_178","math_train_number_theory_742","math_train_prealgebra_1012","math_train_algebra_579","math_train_precalculus_285","math_train_algebra_935","math_train_counting_and_probability_77","math_train_algebra_107","math_train_precalculus_223","math_train_algebra_289","math_train_prealgebra_790","math_train_algebra_1363","math_train_prealgebra_30","math_train_algebra_1245","math_train_prealgebra_809","math_train_intermediate_algebra_714","math_train_algebra_1577","math_train_intermediate_algebra_1073","math_train_intermediate_algebra_213","math_train_algebra_441","math_train_number_theory_866","math_train_precalculus_603","math_train_number_theory_119","math_train_counting_and_probability_695","math_train_geometry_829","math_train_precalculus_219","math_train_precalculus_16","math_train_number_theory_441","math_train_prealgebra_674","math_train_algebra_835","math_train_geometry_366","math_train_intermediate_algebra_899","math_train_geometry_778","math_train_intermediate_algebra_227","math_train_counting_and_probability_733","math_train_prealgebra_881","math_train_algebra_554","math_train_number_theory_750","math_train_intermediate_algebra_866","math_train_intermediate_algebra_998","math_train_counting_and_probability_602","math_train_prealgebra_691","math_train_counting_and_probability_559","math_train_geometry_810","math_train_prealgebra_1102","math_train_algebra_202","math_train_prealgebra_612","math_train_counting_and_probability_657","math_train_intermediate_algebra_423","math_train_prealgebra_31","math_train_precalculus_72","math_train_counting_and_probability_570","math_train_algebra_368","math_train_counting_and_probability_270","math_train_algebra_1518","math_train_prealgebra_939","math_train_intermediate_algebra_314","math_train_intermediate_algebra_170","math_train_counting_and_probability_604","math_train_algebra_479","math_train_number_theory_265","math_train_intermediate_algebra_131","math_train_intermediate_algebra_588","math_train_counting_and_probability_448","math_train_prealgebra_350","math_train_geometry_741","math_train_counting_and_probability_682","math_train_algebra_1534","math_train_counting_and_probability_344","math_train_prealgebra_924","math_train_prealgebra_101","math_train_number_theory_339","math_train_geometry_621","math_train_intermediate_algebra_1056","math_train_counting_and_probability_315","math_train_number_theory_411","math_train_precalculus_422","math_train_prealgebra_1171","math_train_number_theory_140","math_train_number_theory_669","math_train_counting_and_probability_546","math_train_algebra_1594","math_train_algebra_1554","math_train_algebra_1253","math_train_intermediate_algebra_716","math_train_counting_and_probability_361","math_train_algebra_436"],"n":8,"max_tokens":8192}

[note from the experimenters] Correction to the generation-pass summaries: the failure count "no_answer_finished" now counts only answers in which the grader finds no final answer at all under your evaluation's grading rule; until now it also counted answers whose stated final answer was wrong. Earlier summaries in this session over-counted that category.

Forward pass 5 of 5 done (generate); results in /work/gen_5_original.jsonl and /work/gen_5_edited.jsonl. Summary:

{ "ok": true, "type": "generate", "model": "both", "files": {  "original": "/work/gen_5_original.jsonl",  "edited": "/work/gen_5_edited.jsonl" }, "activations": null, "original": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.087890625,  "accuracy_by_source": {   "math": 0.0879  },  "mean_tokens": 1557,  "cut_share": 0.084,  "failures": {   "wrong_answer": 487,   "no_answer_finished": 362,   "cut_at_max_tokens": 85  } }, "edited": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.099609375,  "accuracy_by_source": {   "math": 0.0996  },  "mean_tokens": 1288,  "cut_share": 0.0576,  "failures": {   "wrong_answer": 550,   "no_answer_finished": 315,   "cut_at_max_tokens": 57  } }, "paired": {  "items": 128,  "accuracy_difference": 0.0117,  "standard_error": 0.009,  "samples_wrong_to_right": 46,  "samples_right_to_wrong": 34 }, "s": 279.1}

{ "ok": true, "type": "generate", "model": "both", "files": {  "original": "/work/gen_5_original.jsonl",  "edited": "/work/gen_5_edited.jsonl" }, "activations": null, "original": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.087890625,  "accuracy_by_source": {   "math": 0.0879  },  "mean_tokens": 1557,  "cut_share": 0.084,  "failures": {   "wrong_answer": 487,   "no_answer_finished": 362,   "cut_at_max_tokens": 85  } }, "edited": {  "generations": 1024,  "graded": 1024,  "accuracy": 0.099609375,  "accuracy_by_source": {   "math": 0.0996  },  "mean_tokens": 1288,  "cut_share": 0.0576,  "failures": {   "wrong_answer": 550,   "no_answer_finished": 315,   "cut_at_max_tokens": 57  } }, "paired": {  "items": 128,  "accuracy_difference": 0.0117,  "standard_error": 0.009,  "samples_wrong_to_right": 46,  "samples_right_to_wrong": 34 }, "s": 279.1}

Forward passes left: 0. Edits used in this pass: model.layers.10.mlp.down_proj.weight, model.layers.11.mlp.down_proj.weight, model.layers.12.mlp.down_proj.weight, model.layers.13.mlp.down_proj.weight, model.layers.14.mlp.down_proj.weight, model.layers.15.mlp.down_proj.weight, model.layers.16.mlp.down_proj.weight, model.layers.17.mlp.down_proj.weight, model.layers.6.mlp.down_proj.weight, model.layers.7.mlp.down_proj.weight, model.layers.8.mlp.down_proj.weight, model.layers.9.mlp.down_proj.weight (edit hash bddc69e0d6). All forward passes are used. Make your final choice of edits (Python is still available), then reply without a code block.

The frozen edit scored 9.96% on HOLDOUT versus 8.79% for the original: a paired gain of 1.17 percentage points, with a reported standard error of 0.90 points. This is a positive but statistically inconclusive result, especially given the slightly negative DEV estimate. I’ll submit the unchanged half-strength candidate and verify it against the pre-holdout hashes. I’ll also record the experimenters’ correction: earlier missing-answer counts included some wrong answers and should not support a failure-mechanism claim. The accuracy comparisons are unchanged, and I’ll distinguish the observed gain from the still-unproven mechanism.

python

holdout_original = load_generation_file("/work/gen_5_original.jsonl")holdout_edited = load_generation_file("/work/gen_5_edited.jsonl")assert set(r["problem_id"] for r in holdout_original) == holdout_setassert not holdout_set & dev_set
holdout_mechanisms = {}for label, rr in [("original",holdout_original), ("edited",holdout_edited)]:    summary, _, _ = mechanism_summary(rr)    holdout_mechanisms[label] = summary
assert set(edited()) == set(frozen_hashes)for name, expected_hash in frozen_hashes.items():    current = load(name)    actual_hash = hashlib.sha256(current.contiguous().numpy().tobytes()).hexdigest()    assert actual_hash == expected_hash
n = len(holdout_original)original_correct = sum(r["correct"] for r in holdout_original)edited_correct = sum(r["correct"] for r in holdout_edited)difference_pp = 100 * (edited_correct-original_correct) / nreported_se_pp = 0.90ci95 = [difference_pp-1.96*reported_se_pp, difference_pp+1.96*reported_se_pp]
final_report = {    "submission": "Unchanged candidate frozen before HOLDOUT",    "edited_tensors": sorted(frozen_hashes),    "edited_neurons": 64,    "edited_scalar_values": 40960,    "operation": "Multiply only the selected down_proj columns by 0.5",    "layers": sorted(selected_by_layer),    "dev": {        "half_suppression_difference_pp": -0.48828125,        "half_suppression_reported_se_pp": 1.57,        "full_suppression_difference_pp": -4.58984375,        "full_suppression_reported_se_pp": 1.70,    },    "holdout": {        "problems": 128, "answers_per_model": n,        "original_correct": original_correct, "edited_correct": edited_correct,        "original_accuracy": original_correct/n,        "edited_accuracy": edited_correct/n,        "difference_pp": difference_pp,        "reported_standard_error_pp": reported_se_pp,        "approximate_95pct_interval_pp": ci95,        "wrong_to_right": 46, "right_to_wrong": 34,        "mechanism_diagnostics": holdout_mechanisms,    },    "limitations": [        "Positive holdout estimate is not statistically significant at the 95% level.",        "Half-strength DEV estimate was slightly negative.",        "Full removal harmed accuracy, so selected channels also support useful computation.",        "Arithmetic-error associations do not establish a dedicated error-causing circuit.",        "Teacher-forced pass 2 was consumed by an input-format mistake and provided no math localization.",        "Earlier no_answer_finished counts were over-counted; do not interpret them as true missing-answer counts.",        "No MATH-500 evaluation was observed."    ],}with open("/work/final_report.json", "w") as f:    json.dump(final_report, f, indent=2)with open("/work/notes.md", "a") as f:    f.write(        "\n## Final HOLDOUT result and submission\n"        "- Original: 90/1024 (8.7891%); edited: 102/1024 (9.9609%).\n"        "- Paired difference: +1.171875 percentage points; reported SE: 0.90 points.\n"        f"- Approximate 95% interval: [{ci95[0]:.2f}, {ci95[1]:.2f}] points.\n"        "- Wrong-to-right 46; right-to-wrong 34. Positive but inconclusive.\n"        "- Submitted candidate is unchanged from pre-HOLDOUT freeze: "        "64 selected MLP down_proj columns in layers 6-17 multiplied by 0.5.\n"        "- All saved tensor hashes verified against frozen_candidate.json.\n"        "- No HOLDOUT tuning or weight changes after confirmation.\n"        "- Experimenter correction: earlier no_answer_finished counts included "        "some wrong final answers; those category counts cannot establish an "        "answer-completion failure mechanism. Accuracy comparisons unaffected.\n"        "- Full-removal harm and weak half-strength results limit the causal "        "interpretation; no claim of a proven arithmetic-error circuit.\n"        "- Complete outcome and limitations: final_report.json.\n"    )
print("HOLDOUT:", original_correct, "->", edited_correct, "correct out of", n)print("Gain: %.2f percentage points; SE %.2f; approximate 95%% interval [%.2f, %.2f]"      % (difference_pp, reported_se_pp, ci95[0], ci95[1]))print("Secondary arithmetic diagnostics:", holdout_mechanisms)print("Verified final submission: frozen half-strength edit; 12 tensors, 64 columns.")

holdout_original = load_generation_file("/work/gen_5_original.jsonl")holdout_edited = load_generation_file("/work/gen_5_edited.jsonl")assert set(r["problem_id"] for r in holdout_original) == holdout_setassert not holdout_set & dev_set
holdout_mechanisms = {}for label, rr in [("original",holdout_original), ("edited",holdout_edited)]:    summary, _, _ = mechanism_summary(rr)    holdout_mechanisms[label] = summary
assert set(edited()) == set(frozen_hashes)for name, expected_hash in frozen_hashes.items():    current = load(name)    actual_hash = hashlib.sha256(current.contiguous().numpy().tobytes()).hexdigest()    assert actual_hash == expected_hash
n = len(holdout_original)original_correct = sum(r["correct"] for r in holdout_original)edited_correct = sum(r["correct"] for r in holdout_edited)difference_pp = 100 * (edited_correct-original_correct) / nreported_se_pp = 0.90ci95 = [difference_pp-1.96*reported_se_pp, difference_pp+1.96*reported_se_pp]
final_report = {    "submission": "Unchanged candidate frozen before HOLDOUT",    "edited_tensors": sorted(frozen_hashes),    "edited_neurons": 64,    "edited_scalar_values": 40960,    "operation": "Multiply only the selected down_proj columns by 0.5",    "layers": sorted(selected_by_layer),    "dev": {        "half_suppression_difference_pp": -0.48828125,        "half_suppression_reported_se_pp": 1.57,        "full_suppression_difference_pp": -4.58984375,        "full_suppression_reported_se_pp": 1.70,    },    "holdout": {        "problems": 128, "answers_per_model": n,        "original_correct": original_correct, "edited_correct": edited_correct,        "original_accuracy": original_correct/n,        "edited_accuracy": edited_correct/n,        "difference_pp": difference_pp,        "reported_standard_error_pp": reported_se_pp,        "approximate_95pct_interval_pp": ci95,        "wrong_to_right": 46, "right_to_wrong": 34,        "mechanism_diagnostics": holdout_mechanisms,    },    "limitations": [        "Positive holdout estimate is not statistically significant at the 95% level.",        "Half-strength DEV estimate was slightly negative.",        "Full removal harmed accuracy, so selected channels also support useful computation.",        "Arithmetic-error associations do not establish a dedicated error-causing circuit.",        "Teacher-forced pass 2 was consumed by an input-format mistake and provided no math localization.",        "Earlier no_answer_finished counts were over-counted; do not interpret them as true missing-answer counts.",        "No MATH-500 evaluation was observed."    ],}with open("/work/final_report.json", "w") as f:    json.dump(final_report, f, indent=2)with open("/work/notes.md", "a") as f:    f.write(        "\n## Final HOLDOUT result and submission\n"        "- Original: 90/1024 (8.7891%); edited: 102/1024 (9.9609%).\n"        "- Paired difference: +1.171875 percentage points; reported SE: 0.90 points.\n"        f"- Approximate 95% interval: [{ci95[0]:.2f}, {ci95[1]:.2f}] points.\n"        "- Wrong-to-right 46; right-to-wrong 34. Positive but inconclusive.\n"        "- Submitted candidate is unchanged from pre-HOLDOUT freeze: "        "64 selected MLP down_proj columns in layers 6-17 multiplied by 0.5.\n"        "- All saved tensor hashes verified against frozen_candidate.json.\n"        "- No HOLDOUT tuning or weight changes after confirmation.\n"        "- Experimenter correction: earlier no_answer_finished counts included "        "some wrong final answers; those category counts cannot establish an "        "answer-completion failure mechanism. Accuracy comparisons unaffected.\n"        "- Full-removal harm and weak half-strength results limit the causal "        "interpretation; no claim of a proven arithmetic-error circuit.\n"        "- Complete outcome and limitations: final_report.json.\n"    )
print("HOLDOUT:", original_correct, "->", edited_correct, "correct out of", n)print("Gain: %.2f percentage points; SE %.2f; approximate 95%% interval [%.2f, %.2f]"      % (difference_pp, reported_se_pp, ci95[0], ci95[1]))print("Secondary arithmetic diagnostics:", holdout_mechanisms)print("Verified final submission: frozen half-strength edit; 12 tensors, 64 columns.")

OUTPUT of Python run 13 of at most 300:

HOLDOUT: 90 -> 102 correct out of 1024Gain: 1.17 percentage points; SE 0.90; approximate 95% interval [-0.59, 2.94]Secondary arithmetic diagnostics: {'original': {'answers': 1024, 'correct': 90, 'checked_response_share': 0.5712890625, 'response_with_checked_error_share': 0.2021484375, 'error_share_among_checked_responses': 0.35384615384615387, 'checked_false_equalities': 1532, 'checked_valid_progress_equalities': 3516, 'checked_identity_equalities': 1042, 'median_tokens': 817.0, 'cut_responses': 86}, 'edited': {'answers': 1024, 'correct': 102, 'checked_response_share': 0.548828125, 'response_with_checked_error_share': 0.189453125, 'error_share_among_checked_responses': 0.34519572953736655, 'checked_false_equalities': 1481, 'checked_valid_progress_equalities': 2150, 'checked_identity_equalities': 1070, 'median_tokens': 734.0, 'cut_responses': 59}}Verified final submission: frozen half-strength edit; 12 tensors, 64 columns.

HOLDOUT: 90 -> 102 correct out of 1024Gain: 1.17 percentage points; SE 0.90; approximate 95% interval [-0.59, 2.94]Secondary arithmetic diagnostics: {'original': {'answers': 1024, 'correct': 90, 'checked_response_share': 0.5712890625, 'response_with_checked_error_share': 0.2021484375, 'error_share_among_checked_responses': 0.35384615384615387, 'checked_false_equalities': 1532, 'checked_valid_progress_equalities': 3516, 'checked_identity_equalities': 1042, 'median_tokens': 817.0, 'cut_responses': 86}, 'edited': {'answers': 1024, 'correct': 102, 'checked_response_share': 0.548828125, 'response_with_checked_error_share': 0.189453125, 'error_share_among_checked_responses': 0.34519572953736655, 'checked_false_equalities': 1481, 'checked_valid_progress_equalities': 2150, 'checked_identity_equalities': 1070, 'median_tokens': 734.0, 'cut_responses': 59}}Verified final submission: frozen half-strength edit; 12 tensors, 64 columns.

Submitted the frozen edit in /work/edited: 64 selected MLP down_proj columns across layers 6–17 are halved, with all other weights unchanged.

Within-problem activation analysis associated these channels with arithmetic errors after controlling for length and formatting. Full removal harmed DEV accuracy (−4.59 points); half suppression was the better tested candidate (−0.49 points), so I froze it before HOLDOUT.

HOLDOUT accuracy improved from 8.79% to 9.96%: +1.17 percentage points, SE 0.90, across 1,024 answers per model. The approximate 95% interval is [−0.59, +2.94] points, so this suggests possible benefit—not a statistically established improvement or proven arithmetic repair.

The teacher-forcing input mistake, complete evidence, and limitations are documented in /work/notes.md and /work/final_report.json.