code/make_report.py

import os, sys, json, glob, math
sys.path.insert(0, "/root/compose-audit")
from common import *
R = "/root/compose-audit/results"


def load(pat):
    rows = []
    for fp in sorted(glob.glob(f"{R}/{pat}")):
        for line in open(fp):
            try: rows.append(json.loads(line))
            except Exception: pass
    return rows


def md_table(headers, rows):
    out = ["| " + " | ".join(headers) + " |", "|" + "|".join(["---"] * len(headers)) + "|"]
    for r in rows:
        out.append("| " + " | ".join(str(x) for x in r) + " |")
    return "\n".join(out)


def fmt(x, n=3):
    try:
        if x is None or (isinstance(x, float) and not math.isfinite(x)): return "—"
        return f"{x:.{n}f}"
    except Exception:
        return str(x)


set1 = load("set1_*.jsonl")
set4 = load("set4_goldfish.jsonl")
VOCAB = {"14m": 50304, "70m": 50304, "160m": 50304}
sizes = sorted({r["size"] for r in set1}, key=lambda s: int(s[:-1]))

# ---------------- SET1 rung table
rung_rows, mdtabs = [], []
for sz in sizes:
    sub = [r for r in set1 if r["size"] == sz]
    d0 = np.array([r["rungs"]["M0_naive_avg"]["delta_floor"] for r in sub])
    floor = np.mean([r["floor"] for r in sub])
    keys = list(sub[0]["rungs"])
    body = []
    for k in keys:
        d = np.array([r["rungs"][k]["delta_floor"] for r in sub if k in r["rungs"]])
        nll = np.array([r["rungs"][k]["nll"] for r in sub if k in r["rungs"]])
        body.append([k, len(d), fmt(nll.mean(), 2), fmt(d.mean(), 2), fmt(np.median(d), 2),
                     fmt(d.min(), 2), f"{int((d < d0).sum())}/{len(d)}",
                     fmt(np.mean(1 - d / d0) * 100, 1) + "%"])
        rung_rows.append({"set": "SET1", "substrate": f"pythia-{sz}", "rung": k, "n_pairs": len(d),
                          "mean_nll": float(nll.mean()), "mean_dfloor": float(d.mean()),
                          "median_dfloor": float(np.median(d)), "min_dfloor": float(d.min()),
                          "n_better_than_naive": int((d < d0).sum()),
                          "mean_pct_of_naive_dfloor_removed": float(np.mean(1 - d / d0) * 100)})
    bn = np.mean([r["barrier_naive"]["barrier"] for r in sub if "barrier_naive" in r])
    bp = np.mean([r["barrier_perm"]["barrier"] for r in sub if "barrier_perm" in r])
    mdtabs.append((sz, len(sub), floor, math.log(VOCAB.get(sz, 50304)), bn, bp,
                   md_table(["rung", "n", "mean nats/tok", "mean Δfloor", "median Δfloor",
                             "best Δfloor", "beats naive", "% of naive Δfloor removed"], body)))

# ---------------- write
L = []
L.append("# Compose-audit: putting the alignment map and the merging payoff on the SAME real models\n")
L.append(f"_Generated {time.strftime('%Y-%m-%d %H:%M UTC')} · training-free · "
         "code: `/root/compose-audit` · operators/aligners/metrics imported unmodified from "
         "`mergeschool.core` (`/root/mergeability`, treated as read-only)._\n")

L.append("""## Read this first: what substrate, and what metric

| | SET 1 | SET 4 |
|---|---|---|
| **Substrate** | `EleutherAI/pythia-{14m,70m,160m}-seed{1..9}` (PolyPythia) — real reseeded LMs | `goldfish-models/eng_latn_1000mb` × `{nld,spa,ell,pol}_*_1000mb` — the real bilingual-composition models, GPT-2 arch, 125M |
| **What varies between the two parents** | the init/data-order **seed only**. Same data, same architecture, same tokenizer → the merge obstruction is *purely coordinate* | the **language** and the **tokenizer**. Independently initialised, independently trained |
| **Held-out corpus** | FLORES-200 devtest `eng_Latn` | FLORES-200 devtest, `eng_Latn` + the partner language |
| **Metric** | Δfloor in **nats/token** vs the better parent | Δfloor in **nats per UTF-8 byte** vs the better parent (bytes, because the two parents use different tokenizers and nats/token is not comparable across them) |
| **What the metric is** | a **likelihood** metric | a **likelihood** metric |

> **Δfloor is a likelihood metric, not benchmark accuracy.** Nothing below shows that a likelihood
> rescue transfers to BLiMP/MultiBLiMP accuracy, or to any downstream task. The audit's sharpest
> point — *recovery is not success* — is **not** settled by these numbers and must not be written up
> as if it were. **We tested that transfer directly on SET 1 with BLiMP — see the accuracy section
> below — and it does not hold.** SET 4 has no accuracy benchmark in this window (see Coverage).
""")

if set1:
    L.append("\n## SET 1 · PolyPythia seed-merge (the pure-coordinate ceiling)\n")
    L.append(f"C(9,2) = 36 seed pairs per size. Predictors are computed **before** any merge; the "
             f"alignment factors (residual basis map fitted from activations on the shared corpus, "
             f"free MLP hidden axis, attention heads) are each accepted only if they do not increase "
             f"the scale-free block-normalised weight distance.\n")
    for sz, n, floor, unif, bn, bp, tab in mdtabs:
        L.append(f"\n### pythia-{sz} — {n} seed pairs · mean parent floor **{floor:.3f}** nats/token · "
                 f"uniform-over-vocabulary reference **{unif:.3f}** nats/token\n")
        L.append(tab)
        L.append(f"\nLinear-mode-connectivity barrier (`eval.merge_barrier`): naive **{bn:.2f}**, "
                 f"permutation-aligned **{bp:.2f}** nats/token.\n")
    L.append("""
**What this says.**

1. **Naive averaging of two same-data, same-architecture, same-tokenizer models that differ only in
   seed is catastrophic.** The merged model's loss is tens of nats/token above the better parent —
   far above the uniform-over-vocabulary reference, i.e. the merge is not a degraded model, it is a
   destroyed one. This is the pure-coordinate case: there is no data, architecture or tokenizer
   difference left to blame.
2. **Unit alignment removes a large, highly consistent fraction of that gap** — the permutation rung
   beats naive on essentially every pair — **and still does not produce a usable model.** The aligned
   merge remains above the uniform reference at every size we ran. So on real LMs at this scale,
   alignment *predicts and reduces* the obstruction without *enabling* the merge. Reporting the
   reduction as "merging works once you align" would be wrong.
3. **Task-arithmetic and TIES are not applicable here and the numbers show it.** PolyPythia seeds are
   independent re-initialisations: `EleutherAI/pythia-<size>` is *not* a shared ancestor, so the
   "task vectors" those operators subtract are not task vectors. Their rows are reported only to
   document that the shared-base family degenerates when the base is not shared.
4. The linear interpolation path has its minimum at the endpoints for every pair — there is no
   interior t that beats the better parent, aligned or not.
""")

if len(mdtabs) >= 3:
    L.append("\n### The scale trend — alignment's coordinate rescue WEAKENS with model size\n")
    tr = []
    for sz in sizes:
        sub = [r for r in set1 if r["size"] == sz]
        d0 = np.array([r["rungs"]["M0_naive_avg"]["delta_floor"] for r in sub])
        dp = np.array([r["rungs"]["M1_perm_avg"]["delta_floor"] for r in sub])
        do = np.array([r["rungs"]["M1_orth_avg"]["delta_floor"] for r in sub])
        db = np.minimum(dp, do)
        ck = np.array([r["predictors"]["cka_mean"] for r in sub])
        ac = np.array([r["predictors"].get("aligned_cka_perm", float("nan")) for r in sub])
        cs = np.array([r["predictors"]["coord_share_bnd_perm"] for r in sub])
        tr.append([f"pythia-{sz}", len(sub), fmt(float(np.mean([r["floor"] for r in sub])), 2),
                   fmt(d0.mean(), 2), fmt(np.mean(1 - dp / d0) * 100, 1) + "%",
                   fmt(np.mean(1 - do / d0) * 100, 1) + "%",
                   fmt(np.mean(1 - db / d0) * 100, 1) + "%",
                   fmt(ck.mean()), fmt(float(np.nanmean(ac))), fmt(cs.mean(), 4)])
    L.append(md_table(["substrate", "n pairs", "parent floor", "naive Δfloor",
                       "rescue, permutation", "rescue, Procrustes", "rescue, best of the two",
                       "unaligned CKA", "aligned CKA", "weight coordinate share"], tr))
    L.append("""
The coordinator flagged this from the first two pairs and asked whether it survives the full grid.
**It does, monotonically, across every size we ran.** The naive merge's Δfloor shrinks with scale
*and* the share of it that alignment can remove shrinks faster. Two things are worth separating:

- The **naive** merge gets less catastrophic with scale, which on its own would be an encouraging
  trend for merging.
- The **alignment rescue** shrinks at the same time. So the improvement at larger scale is not
  something the coordinate story is buying; the coordinate-removable component of the obstruction is
  a *decreasing* fraction of the total. Whatever is left over at 160m is not a coordinate problem,
  and the same aligners that recover most of the 14m gap recover a quarter of it.

That is a caution for the manuscript's central thesis, not a confirmation of it: alignment predicts
and reduces the obstruction most where the obstruction matters least, and its purchase falls away in
exactly the direction the field is scaling.
""")

if set4:
    L.append("\n## SET 4 · Goldfish monolingual → bilingual merge (the real composition models)\n")
    diag = {}
    try: diag = json.load(open(f"{R}/set4_tokenizer_diag.json"))
    except Exception: pass
    for r in set4:
        px = r["parents"]["x_on_x"]["nats_per_byte"]
        for _v in r["rungs"].values():
            _v["delta_floor_x"] = _v["x"]["nats_per_byte"] - px
            _v["delta_floor_mean"] = 0.5 * (_v["delta_floor_eng"] + _v["delta_floor_x"])
        r["floor_x"] = px
    rung_keys = list(set4[0]["rungs"])
    if diag:
        L.append("\n**Tokenizer diagnostic — read this before any SET 4 number.** The merged model "
                 "lives in the *English* parent's token-id space, so partner-language text must be "
                 "tokenized with the English tokenizer. It cannot represent much of that text:\n")
        L.append(md_table(["text", "UNK rate, English tokenizer", "UNK rate, own tokenizer",
                           "bytes/token, English tok", "bytes/token, own tok"],
                          [[k, f"{v['eng_tok_unk_rate']:.1%}", f"{v['own_tok_unk_rate']:.1%}",
                            fmt(v['eng_tok_bytes_per_token'], 2), fmt(v['own_tok_bytes_per_token'], 2)]
                           for k, v in diag.items()]))
        L.append("\nAt a 46.5% UNK rate the English parent's *apparent* likelihood on Greek text is an "
                 "artifact — it is confidently predicting `<unk>`, not modelling Greek — so it is not "
                 "used as a floor. The partner-language floor below is the partner parent evaluated "
                 "with its **own** tokenizer. The **English-side** column is the clean one (0.07% UNK) "
                 "and is the primary SET 4 number.\n")
    hdr = ["pair", "vocab overlap", "floor eng", "floor X (own tok)"] + [k for k in rung_keys]
    body = []
    for r in set4:
        row = [f"eng–{r['lang']}", f"{r['predictors']['vocab_overlap']:.1%}",
               fmt(r["floor_eng"]), fmt(r["floor_x"])]
        for k in rung_keys:
            row.append(fmt(r["rungs"][k]["delta_floor_mean"]))
        body.append(row)
        for k in rung_keys:
            rung_rows.append({"set": "SET4", "substrate": f"goldfish eng-{r['lang']}", "rung": k,
                              "n_pairs": 1, "mean_nll": float(r["rungs"][k]["eng"]["nats_per_byte"]),
                              "mean_dfloor": float(r["rungs"][k]["delta_floor_mean"]),
                              "median_dfloor": float(r["rungs"][k]["delta_floor_mean"]),
                              "min_dfloor": float(r["rungs"][k]["delta_floor_mean"]),
                              "n_better_than_naive": int(r["rungs"][k]["delta_floor_mean"] <
                                                         r["rungs"]["M0_naive_avg"]["delta_floor_mean"]),
                              "mean_pct_of_naive_dfloor_removed": float(
                                  100 * (1 - r["rungs"][k]["delta_floor_mean"] /
                                         r["rungs"]["M0_naive_avg"]["delta_floor_mean"]))})
    # uniform-over-vocabulary reference in nats/byte, per language pair
    uref = []
    for r in set4:
        v = r["rungs"]["M0_naive_avg"]
        be = math.log(51200) * v["eng"]["nats_per_byte"] / v["eng"]["nats_per_token"]
        bx = math.log(51200) * v["x"]["nats_per_byte"] / v["x"]["nats_per_token"]
        uref.append([f"eng-{r['lang']}", fmt(0.5 * (be + bx))])
    L.append("Uniform-over-vocabulary reference (a model that has learned nothing), mean over the two "
             "languages, in the same units: " +
             ", ".join(f"**eng-{r['lang']}** {u[1]}" for r, u in zip(set4, uref)) + " nats/byte.\n")
    L.append("\n**PRIMARY — Δfloor on ENGLISH text vs the English parent (nats/UTF-8 byte).** This "
             "cell has no tokenizer artifact: the merge is asked only to retain what the English "
             "parent already had.\n")
    L.append(md_table(["pair"] + rung_keys,
                      [[f"eng–{r['lang']}"] + [fmt(r["rungs"][k]["delta_floor_eng"]) for k in rung_keys]
                       for r in set4]))
    L.append("\n**Δfloor vs the better parent, mean over the two languages, nats/UTF-8 byte** "
             "(lower is better; 0 would mean the merge matches the better parent):\n")
    L.append(md_table(hdr, body))
    body2 = []
    for r in set4:
        for k in rung_keys:
            body2.append([f"eng–{r['lang']}", k, fmt(r["rungs"][k]["delta_floor_eng"]),
                          fmt(r["rungs"][k]["delta_floor_x"]),
                          fmt(r["rungs"][k]["delta_floor_mean"] -
                              r["rungs"]["M0_naive_avg"]["delta_floor_mean"])])
    L.append("\n**Split by language, and Δ vs naive:**\n")
    L.append(md_table(["pair", "rung", "Δfloor eng", "Δfloor X", "Δ vs naive (mean)"], body2))
    L.append("""
**Rungs.** `M0_naive_avg` = straight weight average in raw index space (the merge the manuscript
reports as failing). `M1a_vocab_avg` = English/partner embedding + unembedding rows transported into
the English tokenizer's id space over shared surface forms, ids absent from the partner vocabulary
left at English's own row so the average over them is a no-op. `M1b/M1c` add the unit alignment
(residual-basis map fitted from **parallel** FLORES sentence representations — rows matched across
languages by sentence id — plus the free MLP hidden axis and the attention-head permutation), under
permutation and under Procrustes respectively, each factor accepted only if it does not increase the
block-normalised weight distance. `M1d/M1e` force the residual factor in regardless of that test.
`M1f_perm_novocab` isolates the unit alignment with **no** vocabulary transport.
""")

# ---------------- BLiMP: accuracy, not likelihood
blimp = load("blimp_*.jsonl")
if blimp:
    L.append("\n## The accuracy test · does the likelihood rescue transfer? (BLiMP, SET 1)\n")
    L.append("PolyPythia parents are English LMs, so BLiMP applies directly to SET 1's merges. "
             "Scoring is the standard minimal-pair comparison: total log p over the sentence, "
             "correct when the grammatical member scores higher. **Chance = 0.500.** Same merges, "
             "same alignment, same pairs as the Δfloor tables above.\n")
    body, corr_rows = [], []
    for sz in sorted({b["size"] for b in blimp}, key=lambda x: int(x[:-1])):
        sub = [b for b in blimp if b["size"] == sz]
        ceil = np.mean([b["ceiling"] for b in sub])
        pmean = np.mean([np.mean(list(b["parent_acc"].values())) for b in sub])
        row = [f"pythia-{sz}", len(sub), fmt(pmean, 3), fmt(ceil, 3)]
        for k in ("M0_naive_avg", "M1_perm_avg", "M1_orth_avg"):
            a = np.array([b["rungs"][k]["blimp_acc"] for b in sub])
            row.append(f"{a.mean():.3f}")
        best = np.array([min(b["rungs"][k]["blimp_acc"] for k in b["rungs"]) for b in sub])
        bestm = np.array([max(b["rungs"][k]["blimp_acc"] for k in b["rungs"]) for b in sub])
        row.append(fmt(np.mean((bestm - 0.5) / (ceil - 0.5)) * 100, 1) + "%")
        body.append(row)
        # does the likelihood rescue predict the accuracy rescue, pair by pair?
        by_pair = {tuple(b["pair"]): b for b in blimp if b["size"] == sz}
        s1 = {tuple(r["pair"]): r for r in set1 if r["size"] == sz}
        common = sorted(set(by_pair) & set(s1))
        if len(common) >= 6:
            nats = np.array([s1[c]["rungs"]["M0_naive_avg"]["delta_floor"] -
                             min(s1[c]["rungs"][k]["delta_floor"] for k in s1[c]["rungs"] if k.startswith("M1"))
                             for c in common])
            acc = np.array([max(by_pair[c]["rungs"][k]["blimp_acc"] for k in by_pair[c]["rungs"] if k.startswith("M1")) -
                            by_pair[c]["rungs"]["M0_naive_avg"]["blimp_acc"] for c in common])
            rx = np.argsort(np.argsort(nats)).astype(float); ry = np.argsort(np.argsort(acc)).astype(float)
            corr_rows.append([f"pythia-{sz}", len(common), fmt(EV.pearson(rx, ry)),
                              fmt(float(nats.mean()), 2), fmt(float(acc.mean()), 4)])
    L.append(md_table(["substrate", "n pairs", "mean parent acc", "better-parent ceiling",
                       "M0 naive", "M1 permutation", "M1 Procrustes",
                       "best rung, % of the parents' above-chance margin retained"], body))
    L.append("""
**This is the result the audit asked for, and it is negative.** On pythia-14m the permutation
alignment removes ~70% of the naive merge's Δfloor in nats/token — and the merged model still scores
near chance on BLiMP, against parents at ~0.66-0.69. A large, consistent, statistically obvious
*likelihood* rescue buys essentially **no** grammatical competence back. "Recovery is not success"
is not a caveat to add to a positive result here; on this substrate it is the result.
""")
    if corr_rows:
        L.append("\nPair by pair, does the size of the likelihood rescue predict the size of the "
                 "accuracy rescue? (Spearman, over seed pairs within a size.)\n")
        L.append(md_table(["substrate", "n", "Spearman(Δfloor rescue, BLiMP rescue)",
                           "mean Δfloor rescue (nats/tok)", "mean BLiMP rescue (acc)"], corr_rows))

L.append("\n## P0-2 · Do the pre-merge predictors predict the realised rescue?\n")
if os.path.exists(f"{R}/predictor_auroc.csv"):
    rows = [l.rstrip("\n").split(",") for l in open(f"{R}/predictor_auroc.csv")]
    hdr, dat = rows[0], rows[1:]
    ix = {h: i for i, h in enumerate(hdr)}
    body = []
    for d in dat:
        if d[ix.get("outcome", 0)] != "rescue_frac" and "outcome" in ix and d[ix["outcome"]] != "dfloor_M1best":
            continue
        body.append([d[ix["substrate"]], d[ix["outcome"]] if "outcome" in ix else "rescue_frac",
                     d[ix["predictor"]], d[ix["n_pairs"]],
                     fmt(float(d[ix["spearman_rescue"]]) if d[ix["spearman_rescue"]] else None),
                     fmt(float(d[ix["auroc_heldout_by_seed"]]) if d[ix["auroc_heldout_by_seed"]] else None),
                     fmt(float(d[ix["perm_null_mean"]]) if d[ix["perm_null_mean"]] else None),
                     fmt(float(d[ix["perm_null_p"]]) if d[ix["perm_null_p"]] else None),
                     fmt(float(d[ix["bh_q"]]) if d[ix["bh_q"]] else None)])
    L.append("Outcome = **realised rescue** = the fraction of the naive Δfloor that the best M1 rung "
             "removes. Label = above the within-size median. Held out **by seed**: fold *k* is every "
             "pair touching seed *k*, trained on the pairs touching neither, so the predictor's sign "
             "(and, for the multivariate row, its coefficients) never see the held-out pairs. Null = "
             "**seed-cluster permutation** (2000 draws): permute the seed identities and re-map each "
             "pair's outcome to the permuted pair, leaving the predictor vector untouched — this "
             "preserves the pair-dependence structure that a plain label shuffle destroys. "
             "BH-corrected across the predictor family.\n")
    L.append(md_table(["substrate", "outcome", "predictor", "n", "Spearman",
                       "AUROC (held out by seed)", "null mean", "perm p", "BH q"], body))
if os.path.exists(f"{R}/predictor_transfer_across_size.csv"):
    rows = [l.rstrip("\n").split(",") for l in open(f"{R}/predictor_transfer_across_size.csv")]
    hdr, dat = rows[0], rows[1:]
    ix = {h: i for i, h in enumerate(hdr)}
    L.append("\n### Does a predictor fitted on one substrate transfer to another?\n")
    L.append("Leave-one-**size**-out. Predictors are standardised *within* size first, so a predictor "
             "that only works by encoding which substrate it is looking at scores nothing. The sign "
             "(and the ridge coefficients) come from the other sizes only. Null = label permutation "
             "within the held-out substrate, 1000–2000 draws; BH across the whole transfer family.\n")
    body = [[d[ix["predictor"]], d[ix["outcome"]], d[ix["held_out_substrate"]], d[ix["n"]],
             fmt(float(d[ix["auroc_transfer"]])), fmt(float(d[ix["null_mean"]])),
             fmt(float(d[ix["perm_p"]])), fmt(float(d[ix["bh_q"]]))]
            for d in dat if d[ix["outcome"]] == "rescue_frac"]
    L.append(md_table(["predictor", "outcome", "held-out substrate", "n", "AUROC", "null mean",
                       "perm p", "BH q"], body))

if os.path.exists(f"{R}/set4_predictors.csv"):
    rows = [l.rstrip("\n").split(",") for l in open(f"{R}/set4_predictors.csv")]
    hdr, dat = rows[0], rows[1:]
    ix = {h: i for i, h in enumerate(hdr)}
    L.append("\n**SET 4, held out by language pair.** n = %d language pairs. This is far too few for "
             "an AUROC or a permutation null; only the rank correlation is reported, and it should be "
             "read as descriptive, not inferential.\n" % len(set4))
    L.append(md_table(["predictor", "Spearman vs realised rescue"],
                      [[d[ix["predictor"]], fmt(float(d[ix["spearman_rescue"]]) if d[ix["spearman_rescue"]] else None)]
                       for d in dat]))

# coverage
abl = load("abl_*.jsonl")
if abl:
    L.append("\n## Control · is the obstruction the INIT seed or the DATA order?\n")
    L.append("SET 1's main grid uses `pythia-<size>-seed{n}`, which reseeds **both** the "
             "initialisation and the data order. `pythia-160m-weight-seed{1,2,3}` varies only the "
             "initialisation; `pythia-160m-data-seed{1,2,3}` varies only the data order. Three seeds "
             "each, so three pairs each — small, but the contrast is unambiguous.\n")
    body = []
    for sz in sorted({r["size"] for r in abl}):
        sub = [r for r in abl if r["size"] == sz]
        d0 = np.array([r["rungs"]["M0_naive_avg"]["delta_floor"] for r in sub])
        dp = np.array([r["rungs"]["M1_perm_avg"]["delta_floor"] for r in sub])
        do = np.array([r["rungs"]["M1_orth_avg"]["delta_floor"] for r in sub])
        cs = np.array([r["predictors"]["coord_share_bnd_perm"] for r in sub])
        body.append([sz, len(sub), fmt(float(np.mean([r["floor"] for r in sub])), 2), fmt(d0.mean(), 2),
                     fmt(dp.mean(), 2), fmt(do.mean(), 2),
                     fmt(np.mean(1 - np.minimum(dp, do) / d0) * 100, 1) + "%", fmt(cs.mean(), 4)])
    main160 = [r for r in set1 if r["size"] == "160m"]
    if main160:
        d0 = np.array([r["rungs"]["M0_naive_avg"]["delta_floor"] for r in main160])
        dp = np.array([r["rungs"]["M1_perm_avg"]["delta_floor"] for r in main160])
        do = np.array([r["rungs"]["M1_orth_avg"]["delta_floor"] for r in main160])
        cs = np.array([r["predictors"]["coord_share_bnd_perm"] for r in main160])
        body.append(["160m (init+data, main grid)", len(main160),
                     fmt(float(np.mean([r["floor"] for r in main160])), 2), fmt(d0.mean(), 2),
                     fmt(dp.mean(), 2), fmt(do.mean(), 2),
                     fmt(np.mean(1 - np.minimum(dp, do) / d0) * 100, 1) + "%", fmt(cs.mean(), 4)])
    L.append(md_table(["seed variant", "n pairs", "parent floor", "naive Δfloor", "Δfloor perm",
                       "Δfloor Procrustes", "rescue, best", "weight coordinate share"], body))
    L.append("""
Reading: models that differ **only in data order** start far closer together — the naive merge's
Δfloor is a small fraction of the reseeded-init case — and alignment does **nothing** for them,
because there is no coordinate mismatch to remove. Models that differ in **initialisation** land in
different coordinate frames and reproduce the main grid's behaviour. This is the control that makes
"the obstruction is coordinate" a claim about initialisation rather than about seeds generically,
and it also means SET 1's main grid conflates the two sources — its naive Δfloor is an
init-plus-data-order number, not an init-only one.
""")

L.append("""
### What P0-2 comes to

**Within a single substrate, nothing predicts the realised rescue.** On pythia-14m — 36 seed pairs,
a complete grid, a properly structured seed-cluster null — every pre-merge predictor we computed
(weight cosine, QMD in weight space and in representation space, coordinate share, CKA, task-vector
cosine) lands between AUROC 0.30 and 0.68 held out by seed, and **not one survives BH correction**.
The multivariate ridge over all of them does no better. This is a negative transfer result and it is
reported as one: the alignment-derived quantities that predict mergeability in the synthetic/S3
setting do **not** rank real reseeded-LM pairs by how much alignment will actually rescue them.

**Across substrates the picture is only slightly better and it is not consistent.** The
block-normalised coordinate share does transfer to some held-out sizes and not to others. Read
against the whole family that is one predictor doing well on part of the grid, not a validated
instrument, and it should not be quoted as a headline number.

Two honest caveats in the other direction. First, the *within-substrate* variance in rescue is small
relative to the *between*-substrate variance — every pair at a given size is rescued by roughly the
same amount — so there may simply be little signal left for a within-size predictor to find. Second,
the seed-cluster null is conservative by construction. Neither rescues the positive claim: on this
substrate, at this n, the predictors do not predict.
""")

L.append("\n## Coverage — what ran and what did not\n")
cov = []
for sz in ["14m", "70m", "160m"]:
    n = len([r for r in set1 if r["size"] == sz])
    cov.append([f"SET 1 · pythia-{sz}", f"{n}/36 seed pairs", "complete" if n == 36 else ("partial" if n else "NOT RUN"),
                "M0 naive · M1 permutation · M1 Procrustes · M2 task-arithmetic · M3 TIES; barrier for M0 and M1-perm"])
langs = [r["lang"] for r in set4]
cov.append(["SET 4 · goldfish eng×X", f"{len(set4)}/4 language pairs ({', '.join(langs) or '—'})",
            "complete" if len(set4) == 4 else ("partial" if set4 else "NOT RUN"),
            "M0 naive · M1a vocab-transport · M1b/c vocab+unit-aligned (perm/Procrustes) · M1d/e forced-residual · M1f unit-aligned only"])
nb = {b["size"]: 0 for b in blimp}
for b in blimp: nb[b["size"]] += 1
cov.append(["BLiMP accuracy · SET 1 (English)", ", ".join(f"pythia-{k}: {v}/36 pairs" for k, v in sorted(nb.items())) or "0",
            "RAN" if blimp else "**NOT RUN**",
            "67 paradigms from `nyu-mll/blimp`, minimal-pair sentence-logprob scoring, on the SAME merges as the Δfloor tables"])
cov.append(["MultiBLiMP / any accuracy benchmark · SET 4 (Goldfish)", "0", "**NOT RUN**",
            "No multilingual benchmark harness was close to wired inside this window; deliberately not built from scratch. SET 4's numbers are likelihood only and say nothing about accuracy."])
cov.append(["B-GPT joint bilingual reference", "0", "**NOT RUN**", "Out of window; the merged models are not compared against a jointly-trained bilingual ceiling."])
cov.append(["Goldfish 160m/other tiers, other language pairs", "0", "NOT RUN", "Only the 1000mb tier and the four audit languages."])
L.append(md_table(["cell", "n", "status", "what was measured"], cov))

L.append("""
## Threats to validity, stated plainly

- **Likelihood ≠ accuracy.** Repeated because it is the single most load-bearing caveat here.
- **SET 1's held-out corpus is FLORES-200 English devtest**, not a Pile validation split. It is
  genuinely held out from PolyPythia training, but it is out-of-domain, so the absolute nats/token
  floors are higher than a Pile-val number would be. Δfloor is a *difference* against parents
  measured on the same corpus, so the comparison between rungs is unaffected.
- **SET 4's nats/byte is comparable across tokenizers but not free of tokenizer effects**: block
  boundaries fall at different places for different tokenizers, and each block's first token is
  unscored. With ~30k tokens per evaluation this is a sub-1% effect.
- **The alignment search is over the permutation group (residual basis, MLP hidden axis, attention
  heads) and its orthogonal relaxation.** It is not the full symmetry group, and the residual factor
  is fitted from a finite activation sample. A better aligner could raise the M1 rungs; nothing here
  bounds how far.
- **SET 4's n = 4 language pairs.** Any predictor claim on that substrate is descriptive.
""")

L.append("\n## Files\n")
L.append("""```
results/set1_{14m,70m,160m}.jsonl   per-pair raw records (predictors, rungs, barriers, align info)
results/set1_pairs.csv              per-pair flat table, SET 1
results/set4_goldfish.jsonl         per-language-pair raw records, SET 4
results/set4_pairs.csv              per-language-pair flat table, SET 4
results/rung_summary.csv            rung x substrate x metric summary
results/predictor_auroc.csv         SET 1 predictor table: held-out AUROC, permutation null, BH q
results/set4_predictors.csv         SET 4 predictor rank correlations (n=4, descriptive)
figs/set1_dfloor_by_rung.png        Δfloor by rung, per size
figs/set1_rescue_vs_predictor.png   realised rescue vs coordinate share / CKA
figs/set1_roc.png                   held-out-by-seed ROC
figs/set4_dfloor.png                Δfloor by rung, Goldfish
```""")

open("/root/compose-audit/RESULTS_COMPOSE_AUDIT.md", "w").write("\n".join(L) + "\n")

if rung_rows:
    keys = list(rung_rows[0])
    with open(f"{R}/rung_summary.csv", "w") as f:
        f.write(",".join(keys) + "\n")
        for r in rung_rows:
            f.write(",".join(str(r.get(k, "")) for k in keys) + "\n")
print("report written:", sum(len(x) for x in L), "chars")