Create ar_differentiation_bed.py

ar_differentiation_bed.py

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+"""ar_differentiation_bed.py — THE FOCUS (2026-07-09 redirect, Phil verbatim):
+"refining the autoregressive techniques for differentiation rather than attempting
+to just mash numbers together."
+
+Differentiation is cultivated by PREDICTIVE pressure along the sequence — the
+address parameterizing the next-byte distribution (Law 2: chain-rule advantage pays
+ONLY where the composed address directly parameterizes the predictive distribution).
+This bed puts the aleph in the autoregressive gradient path and measures what
+differentiates. It is the Law-2 construction (codebook-pressure C3) + Tree 3d in
+one harness; the Jun-19 "discuss before building" gate was resolved by the redirect.
+
+Byte-level causal LM on wikitext-2-raw (HF parquet, CDN-fast), block 256. ARMS:
+  sdpa       — standard causal transformer control (matched trunk).
+  hub        — attention replaced by CAUSAL HUB: linear attention whose feature map
+               is the 2K-oriented aleph address, prefix-sum memories (no selection
+               event; O(n*K*d)). Differentiation cultivated INSIDE attention.
+  addr_head  — sdpa trunk, but the OUTPUT HEAD reads ONLY the signed aleph
+               coefficient vector w_k = sinh(u_k)/sum_j cosh(u_j) of the final
+               hidden state (K -> 256 logits). The address MUST carry every bit of
+               next-byte information — the hardest Law-2 bottleneck.
+
+JUDGED BY: val bits-per-byte per arm (task) + CULTIVATION VITALS on every aleph
+codebook (readouts, never losses): axis aliveness/hppl, drift-from-init +
+binding fraction @0.29154, winner-|cos| saturation (sign-code emergence), shadow
+path diversity (fixed high-bits hash). Never by recon.
+
+Riders: pure Adam wd=0; no BN/Dropout/GAP on geometric paths; orthogonal init;
+Colab-cell-safe (paste-ahead imports, no bare argparse, no __file__ reliance);
+GPU-only for verdict runs; data_root OUTSIDE the mind repo.
+
+Terminal:  python ar_differentiation_bed.py            # shapes/parse smoke
+           python ar_differentiation_bed.py --train    # verdict run
+Colab:     paste geolip_vitals.py cell, then this file (smoke auto-runs),
+           then  train(steps=2000, data_root="/content/data")  in the next cell.
+
+Author: AbstractPhil + Claude
+Home: https://huggingface.co/AbstractPhil
+License: MIT
+
+"""
+from __future__ import annotations
+import math
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+if "anchor_drift" not in globals():
+    try:
+        from geolip_vitals import anchor_drift, axis_aliveness, path_diversity
+    except ImportError:
+        _here = globals().get("__file__")
+        if _here is not None:
+            import sys, pathlib
+            sys.path.insert(0, str(pathlib.Path(_here).parent))
+            from geolip_vitals import anchor_drift, axis_aliveness, path_diversity
+        else:
+            raise ImportError(
+                "geolip_vitals not found — paste/run its cell first, or "
+                "hf_hub_download tools/geolip_vitals.py from AbstractPhil/claude-mind.")
+
+VOCAB = 256  # bytes
+
+
+# ------------------------------------------------------------------ aleph address
+def _super_fibonacci_s3(n: int) -> torch.Tensor:
+    """Near-uniform unit quaternions (Alexa CVPR'22; constants per canon) —
+    starts the codebook INSIDE the RP^3 attractor basin. D=4 only."""
+    PHI, PSI = math.sqrt(2.0), 1.533751168755204288118041
+    i = torch.arange(n, dtype=torch.float64)
+    s = (i + 0.5) / n
+    r, R = torch.sqrt(s), torch.sqrt(1.0 - s)
+    a, b = 2 * math.pi * i / PHI, 2 * math.pi * i / PSI
+    q = torch.stack([r * torch.sin(a), r * torch.cos(a),
+                     R * torch.sin(b), R * torch.cos(b)], dim=-1)
+    return F.normalize(q, dim=-1).float()
+
+
+class AlephAddress(nn.Module):
+    """Closed-form aleph over 2K oriented half-axes (canon/aleph_core.md).
+    signed(x): (..., K) w_k = sinh(u_k)/sum_j cosh(u_j)   — the Law-2 head feature.
+    oriented(x): ((..., K), (..., K)) positive halves of the 2K softmax — HUB map."""
+
+    def __init__(self, K: int, D: int, tau: float = 0.1, init: str = "random"):
+        super().__init__()
+        self.K, self.D, self.tau = K, D, tau
+        if init == "fibonacci":
+            assert D == 4, "fibonacci init lives on S^3 (D=4)"
+            A = _super_fibonacci_s3(K)
+        else:
+            A = F.normalize(torch.randn(K, D), dim=-1)
+        self.codebook = nn.Parameter(A)
+        self.register_buffer("home", self.codebook.detach().clone())
+
+    def _u(self, x):
+        A = F.normalize(self.codebook, dim=-1)
+        return (F.normalize(x, dim=-1) @ A.transpose(-1, -2)) / self.tau
+
+    def oriented(self, x):
+        u = self._u(x)
+        m = u.abs().amax(dim=-1, keepdim=True)
+        ep, en = torch.exp(u - m), torch.exp(-u - m)
+        Z = (ep + en).sum(dim=-1, keepdim=True)
+        return ep / Z, en / Z
+
+    def signed(self, x):
+        u = self._u(x)
+        m = u.abs().amax(dim=-1, keepdim=True)
+        ep, en = torch.exp(u - m), torch.exp(-u - m)
+        return (ep - en) / (ep + en).sum(dim=-1, keepdim=True)
+
+    def signed_at(self, x, taus):
+        """Multi-tau stroboscope (rule of 3): signed coefficients at several
+        temperatures, concatenated — softer taus keep the vector dense while a
+        hard tau supplies the sign-code sharpness. v2 refinement (b)."""
+        A = F.normalize(self.codebook, dim=-1)
+        cos = F.normalize(x, dim=-1) @ A.transpose(-1, -2)
+        outs = []
+        for t in taus:
+            u = cos / t
+            m = u.abs().amax(dim=-1, keepdim=True)
+            ep, en = torch.exp(u - m), torch.exp(-u - m)
+            outs.append((ep - en) / (ep + en).sum(dim=-1, keepdim=True))
+        return torch.cat(outs, dim=-1)
+
+    def m_hat(self, x):
+        """Closed-form soft read (decoders read M_hat, never M). v2 control (c)."""
+        u = self._u(x)
+        m = u.abs().amax(dim=-1, keepdim=True)
+        ep, en = torch.exp(u - m), torch.exp(-u - m)
+        A = F.normalize(self.codebook, dim=-1)
+        return ((ep - en) @ A) / (ep + en).sum(dim=-1, keepdim=True)
+
+    def m_hard_ste(self, x):
+        """Canon hard mode: M_hard = sign(cos_win) * A[win], straight-through to
+        the soft read — forward fully discrete SIGN CODE, backward soft gradient.
+        Legal per theme A (reconstructive sign code, not a one-hot roster pick)."""
+        u = self._u(x)
+        soft = self.m_hat(x)
+        win = u.abs().argmax(dim=-1)
+        A = F.normalize(self.codebook, dim=-1)
+        sign = torch.sign(torch.gather(u, -1, win.unsqueeze(-1))).squeeze(-1)
+        hard = sign.unsqueeze(-1) * A[win]
+        return hard + soft - soft.detach()
+
+    @torch.no_grad()
+    def vitals(self, x_sample) -> dict:
+        u = self._u(x_sample.reshape(-1, x_sample.shape[-1]))
+        p, n = self.oriented(x_sample.reshape(-1, x_sample.shape[-1]))
+        two_k = torch.cat([p, n], dim=-1)
+        win = two_k.argmax(dim=-1)
+        cos_win = (u.abs().amax(dim=-1) * self.tau)  # winner |cos| — sign-code sat.
+        d = anchor_drift(self.codebook, self.home)
+        return {"drift": round(d["mean"], 4),
+                "binding_frac": round(d["binding_fraction"], 4),
+                "aliveness": axis_aliveness(two_k),
+                "win_cos_mean": round(cos_win.mean().item(), 4),
+                "paths": path_diversity(win)}
+
+
+# ------------------------------------------------------------------------- blocks
+class CausalSDPA(nn.Module):
+    def __init__(self, d: int, heads: int = 4):
+        super().__init__()
+        self.h = heads
+        self.qkv = nn.Linear(d, 3 * d, bias=False)
+        self.o = nn.Linear(d, d, bias=False)
+        nn.init.orthogonal_(self.qkv.weight); nn.init.orthogonal_(self.o.weight)
+
+    def forward(self, x):
+        B, n, d = x.shape
+        q, k, v = self.qkv(x).chunk(3, dim=-1)
+        q, k, v = (t.view(B, n, self.h, d // self.h).transpose(1, 2) for t in (q, k, v))
+        y = F.scaled_dot_product_attention(q, k, v, is_causal=True)
+        return self.o(y.transpose(1, 2).reshape(B, n, d))
+
+
+class CausalHUB(nn.Module):
+    """Causal aleph linear attention: prefix-sum memories over the two K-wide
+    halves of the oriented address; 2K never materialized; no selection event."""
+
+    def __init__(self, d: int, K: int = 32, D: int = 4, tau: float = 0.1):
+        super().__init__()
+        self.addr = AlephAddress(K, D, tau)
+        self.q = nn.Linear(d, D, bias=False)
+        self.k = nn.Linear(d, D, bias=False)
+        self.v = nn.Linear(d, d, bias=False)
+        self.o = nn.Linear(d, d, bias=False)
+        for m in (self.q, self.k, self.v, self.o):
+            nn.init.orthogonal_(m.weight)
+
+    def forward(self, x):
+        qp, qn = self.addr.oriented(self.q(x))          # (B, n, K)
+        kp, kn = self.addr.oriented(self.k(x))
+        v = self.v(x)                                    # (B, n, d)
+        Sp = torch.cumsum(torch.einsum("bnk,bnd->bnkd", kp, v), dim=1)
+        Sn = torch.cumsum(torch.einsum("bnk,bnd->bnkd", kn, v), dim=1)
+        zp = torch.cumsum(kp, dim=1)
+        zn = torch.cumsum(kn, dim=1)
+        num = torch.einsum("bnk,bnkd->bnd", qp, Sp) + torch.einsum("bnk,bnkd->bnd", qn, Sn)
+        den = (qp * zp).sum(-1, keepdim=True) + (qn * zn).sum(-1, keepdim=True)
+        return self.o(num / den.clamp_min(1e-12))
+
+
+class MslRelay(nn.Module):
+    """Depth-composition unit (chain-rule probe): multi-slot M_hat read entering
+    the trunk as a NEAR-ZERO gated residual (gate init -3.0, sigma~0.047 — theme D:
+    geometry enters as a nudge and grows only if it earns gradient)."""
+
+    def __init__(self, d: int, n_slots: int = 16, K: int = 64):
+        super().__init__()
+        self.n_slots = n_slots
+        self.proj = nn.Linear(d, n_slots * 4, bias=False)
+        self.out = nn.Linear(n_slots * 4, d, bias=False)
+        nn.init.orthogonal_(self.proj.weight)
+        nn.init.orthogonal_(self.out.weight)
+        self.addr = AlephAddress(K, 4)
+        self.gate = nn.Parameter(torch.tensor(-3.0))
+
+    def forward(self, x):
+        B, n, _ = x.shape
+        slots = self.proj(x).view(B, n, self.n_slots, 4)
+        m = self.addr.m_hat(slots).reshape(B, n, -1)
+        return x + self.gate.sigmoid() * self.out(m)
+
+
+class Block(nn.Module):
+    def __init__(self, d: int, attn: nn.Module):
+        super().__init__()
+        self.n1, self.n2 = nn.LayerNorm(d), nn.LayerNorm(d)
+        self.attn = attn
+        self.mlp = nn.Sequential(nn.Linear(d, 4 * d), nn.GELU(), nn.Linear(4 * d, d))
+
+    def forward(self, x):
+        x = x + self.attn(self.n1(x))
+        return x + self.mlp(self.n2(x))
+
+
+class ByteLM(nn.Module):
+    def __init__(self, arm: str, d: int = 192, layers: int = 4, block: int = 256,
+                 K: int = 32, D: int = 4):
+        super().__init__()
+        # "<arm>_tri" suffix = trigram byte embedding (AlephLM byte_emb x3 lineage):
+        # token embedding is the sum of embeddings of bytes t, t-1, t-2.
+        self.trigram = arm.endswith("_tri")
+        if self.trigram:
+            arm = arm[:-4]
+        # "_fib" = super-Fibonacci S^3 codebook init (basin test: starts INSIDE
+        # the RP^3 attractor; primary observable is init->final geodesic drift).
+        self.fib = arm.endswith("_fib")
+        if self.fib:
+            arm = arm[:-4]
+        # "relay*" = stacked addresses in depth: MslRelay after every block.
+        # relay -> sdpa trunk + standard head; relay_msl64 -> + addressed head.
+        self.use_relay = arm.startswith("relay")
+        if arm == "relay":
+            arm = "sdpa"
+        elif arm == "relay_msl64":
+            arm = "addr_msl64"
+        self.arm, self.block = arm, block
+        self.emb = nn.Embedding(VOCAB, d)
+        if self.trigram:
+            self.emb1 = nn.Embedding(VOCAB, d)
+            self.emb2 = nn.Embedding(VOCAB, d)
+        self.pos = nn.Parameter(torch.zeros(1, block, d) + 0.01 * torch.randn(1, block, d))
+        mk_attn = (lambda: CausalHUB(d, K, D)) if arm == "hub" else (lambda: CausalSDPA(d))
+        self.blocks = nn.ModuleList([Block(d, mk_attn()) for _ in range(layers)])
+        if self.use_relay:
+            self.relays = nn.ModuleList([MslRelay(d) for _ in range(layers)])
+        self.nf = nn.LayerNorm(d)
+        if arm == "addr_head":
+            self.head_addr = AlephAddress(K, d)  # v1: codebook in model dim — COLLAPSED
+            self.head = nn.Linear(K, VOCAB, bias=True)
+        elif arm in ("addr_d4", "addr_3tau", "addr_mhat"):
+            # v2 refinements: LOW-D HOME — learned projection to the canon D=4 home
+            # before addressing (mirrors the healthy HUB arms), K=64.
+            self.head_proj = nn.Linear(d, 4, bias=False)
+            nn.init.orthogonal_(self.head_proj.weight)
+            self.head_addr = AlephAddress(64, 4)
+            if arm == "addr_d4":
+                self.head = nn.Linear(64, VOCAB, bias=True)      # w alone, D=4 home
+            elif arm == "addr_3tau":
+                self.taus = (0.05, 0.1, 0.3)                     # rule-of-3 strobe
+                self.head = nn.Linear(64 * 3, VOCAB, bias=True)
+            else:                                                 # addr_mhat
+                self.head = nn.Linear(4, VOCAB, bias=True)       # tightest: M_hat
+        elif arm.startswith("addr_msl"):
+            # v3: MULTI-SLOT heads — the 16s funnel widening: P parallel D=4 slots
+            # over a SHARED codebook. addr_msl consumes the reconstructive M_hat per
+            # slot (Px4 dims); addr_msl_w consumes signed w per slot (Px64) — tests
+            # whether slot-parallel consumption alone rescues the coefficient path.
+            # addr_msl<P> = slot-count dose-response. addr_mslh<P> = HARD sign-code
+            # consumption (straight-through M_hard per slot).
+            self.hard = arm.startswith("addr_mslh")
+            if arm in ("addr_msl", "addr_msl_w"):
+                self.n_slots = 16
+            else:
+                self.n_slots = int(arm[len("addr_mslh" if self.hard else "addr_msl"):])
+            self.head_proj = nn.Linear(d, self.n_slots * 4, bias=False)
+            nn.init.orthogonal_(self.head_proj.weight)
+            self.head_addr = AlephAddress(
+                64, 4, init="fibonacci" if self.fib else "random")
+            width = self.n_slots * (64 if arm == "addr_msl_w" else 4)
+            self.head = nn.Linear(width, VOCAB, bias=True)
+        elif arm == "addr_3tau_mhat":
+            # v3: combine the two v2 winners — 3-tau stroboscope + reconstructive read.
+            self.head_proj = nn.Linear(d, 4, bias=False)
+            nn.init.orthogonal_(self.head_proj.weight)
+            self.head_addr = AlephAddress(64, 4)
+            self.taus = (0.05, 0.1, 0.3)
+            self.head = nn.Linear(64 * 3 + 4, VOCAB, bias=True)
+        else:
+            self.head = nn.Linear(d, VOCAB, bias=True)
+        self._last_h = None
+
+    def forward(self, idx):
+        x = self.emb(idx)
+        if self.trigram:  # past-only shifts — causality preserved
+            x = x + self.emb1(F.pad(idx, (1, 0), value=0)[:, :-1]) \
+                  + self.emb2(F.pad(idx, (2, 0), value=0)[:, :-2])
+        x = x + self.pos[:, : idx.shape[1]]
+        if self.use_relay:
+            for b, r in zip(self.blocks, self.relays):
+                x = r(b(x))
+        else:
+            for b in self.blocks:
+                x = b(x)
+        h = self.nf(x)
+        self._last_h = h.detach()
+        if self.arm == "addr_head":
+            return self.head(self.head_addr.signed(h))
+        if self.arm == "addr_d4":
+            return self.head(self.head_addr.signed(self.head_proj(h)))
+        if self.arm == "addr_3tau":
+            return self.head(self.head_addr.signed_at(self.head_proj(h), self.taus))
+        if self.arm == "addr_mhat":
+            return self.head(self.head_addr.m_hat(self.head_proj(h)))
+        if self.arm.startswith("addr_msl"):
+            B, n, _ = h.shape
+            slots = self.head_proj(h).view(B, n, self.n_slots, 4)
+            if self.arm == "addr_msl_w":
+                feats = self.head_addr.signed(slots).reshape(B, n, -1)
+            elif getattr(self, "hard", False):
+                feats = self.head_addr.m_hard_ste(slots).reshape(B, n, -1)
+            else:
+                feats = self.head_addr.m_hat(slots).reshape(B, n, -1)
+            return self.head(feats)
+        if self.arm == "addr_3tau_mhat":
+            p = self.head_proj(h)
+            feats = torch.cat([self.head_addr.signed_at(p, self.taus),
+                               self.head_addr.m_hat(p)], dim=-1)
+            return self.head(feats)
+        return self.head(h)
+
+    @torch.no_grad()
+    def vitals(self) -> dict:
+        out = {}
+        if self.arm == "hub":
+            for i, b in enumerate(self.blocks):
+                if self._last_h is not None:
+                    out[f"L{i}"] = b.attn.addr.vitals(b.attn.q(self._last_h[:2]))
+        elif self.arm == "addr_head" and self._last_h is not None:
+            out["head"] = self.head_addr.vitals(self._last_h[:2])
+        elif self.arm in ("addr_d4", "addr_3tau", "addr_mhat",
+                          "addr_3tau_mhat") and self._last_h is not None:
+            out["head"] = self.head_addr.vitals(self.head_proj(self._last_h[:2]))
+        elif self.arm.startswith("addr_msl") and self._last_h is not None:
+            slots = self.head_proj(self._last_h[:2])
+            out["head"] = self.head_addr.vitals(
+                slots.reshape(*slots.shape[:-1], self.n_slots, 4))
+        if self.use_relay and self._last_h is not None:
+            for i, r in enumerate(self.relays):
+                s = r.proj(self._last_h[:2])
+                v = r.addr.vitals(s.reshape(*s.shape[:-1], r.n_slots, 4))
+                out[f"relay{i}"] = {"gate": round(r.gate.sigmoid().item(), 4),
+                                    "drift": v["drift"],
+                                    "binding_frac": v["binding_frac"],
+                                    "ppl": round(v["aliveness"]["usage_ppl"], 1)}
+        return out
+
+
+# --------------------------------------------------------------------------- data
+def _wikitext_bytes(data_root: str):
+    """wikitext-2-raw as flat uint8 tensors via the HF parquet CDN."""
+    from huggingface_hub import hf_hub_download
+    import pyarrow.parquet as pq
+
+    def load(split):
+        p = hf_hub_download("Salesforce/wikitext",
+                            f"wikitext-2-raw-v1/{split}-00000-of-00001.parquet",
+                            repo_type="dataset", local_dir=data_root)
+        text = "".join(pq.read_table(p).column("text").to_pylist())
+        return torch.frombuffer(bytearray(text.encode("utf-8")), dtype=torch.uint8).clone()
+
+    return load("train"), load("validation")
+
+
+def _batch(data: torch.Tensor, batch: int, block: int, device, g: torch.Generator):
+    ix = torch.randint(0, data.numel() - block - 1, (batch,), generator=g)
+    x = torch.stack([data[i:i + block] for i in ix]).long().to(device)
+    y = torch.stack([data[i + 1:i + block + 1] for i in ix]).long().to(device)
+    return x, y
+
+
+# -------------------------------------------------------------------- train/smoke
+def train(arms=("sdpa", "hub", "addr_head"), steps: int = 2000, batch: int = 32,
+          block: int = 256, device: str = "cuda", data_root: str = "./data",
+          seed: int = 0, eval_every: int = 500, save: bool = True):
+    """Verdict run — GPU only. Pure Adam wd=0. Reports val bits-per-byte + vitals.
+    save=True writes {data_root}/ar_ckpts/{arm}_s{seed}_t{steps}.pt per arm —
+    the cultivated codebooks are SPECIMENS for the projective reading instruments."""
+    import os
+    if device == "cuda" and not torch.cuda.is_available():
+        raise RuntimeError("Verdict runs are GPU-only (never CPU-train for accuracy).")
+    ckpt_dir = os.path.join(data_root, "ar_ckpts")
+    os.makedirs(ckpt_dir, exist_ok=True)
+    tr, va = _wikitext_bytes(data_root)
+    print(f"data ready: train {tr.numel():,} bytes, val {va.numel():,} bytes", flush=True)
+    results = {}
+    for arm in arms:
+        torch.manual_seed(seed)
+        g = torch.Generator().manual_seed(seed)
+        model = ByteLM(arm, block=block).to(device)
+        n_params = sum(p.numel() for p in model.parameters())
+        opt = torch.optim.Adam(model.parameters(), lr=3e-4, weight_decay=0.0)
+        for step in range(1, steps + 1):
+            x, y = _batch(tr, batch, block, device, g)
+            logits = model(x)
+            loss = F.cross_entropy(logits.reshape(-1, VOCAB), y.reshape(-1))
+            opt.zero_grad(set_to_none=True)
+            loss.backward()
+            opt.step()
+            if step % eval_every == 0 or step == steps:
+                model.eval()
+                with torch.no_grad():
+                    losses = []
+                    for _ in range(20):
+                        xv, yv = _batch(va, batch, block, device, g)
+                        lv = F.cross_entropy(model(xv).reshape(-1, VOCAB),
+                                             yv.reshape(-1))
+                        losses.append(lv.item())
+                bpb = sum(losses) / len(losses) / math.log(2)
+                print(f"[{arm}] step {step} val_bpb={bpb:.4f} vitals={model.vitals()}",
+                      flush=True)
+                model.train()
+        results[arm] = {"val_bpb": bpb, "params": n_params, "vitals": model.vitals()}
+        if save:
+            path = os.path.join(ckpt_dir, f"{arm}_s{seed}_t{steps}.pt")
+            torch.save({"arm": arm, "seed": seed, "steps": steps, "val_bpb": bpb,
+                        "state_dict": {k: v.cpu() for k, v in
+                                       model.state_dict().items()}}, path)
+            print(f"saved specimen: {path}", flush=True)
+    print(results, flush=True)
+    return results
+
+
+def smoke():
+    """Shapes/parse only — no accuracy claims."""
+    x = torch.randint(0, VOCAB, (2, 64))
+    for arm in ("sdpa", "hub", "addr_head"):
+        m = ByteLM(arm, d=96, layers=2, block=64, K=16)
+        logits = m(x)
+        assert logits.shape == (2, 64, VOCAB)
+        logits.sum().backward()
+        # causality check: future byte must not affect past logits
+        with torch.no_grad():
+            a = m(x)[0, 10]
+            x2 = x.clone(); x2[0, 40] = (x2[0, 40] + 7) % 256
+            b = m(x2)[0, 10]
+        assert torch.allclose(a, b, atol=1e-4), f"{arm} leaks future context"
+        print(f"{arm}: OK params={sum(p.numel() for p in m.parameters()):,} "
+              f"vitals={m.vitals()}", flush=True)
+    print("OK — AR bed smoke passed (verdict run: train() on GPU)", flush=True)
+
+
+def _in_notebook() -> bool:
+    try:
+        get_ipython()  # type: ignore[name-defined]  # noqa: F821
+        return True
+    except NameError:
+        return False
+
+
+if __name__ == "__main__":
+    if _in_notebook():
+        smoke()
+        print("Notebook mode: call  train(steps=2000)  in the next cell (GPU).")
+    else:
+        import argparse
+        ap = argparse.ArgumentParser()
+        ap.add_argument("--train", action="store_true")
+        ap.add_argument("--steps", type=int, default=2000)
+        a, _ = ap.parse_known_args()
+        train(steps=a.steps) if a.train else smoke()