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3646c00 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | #!/usr/bin/env python3
"""J-SPACE analyzer — advanced (after Anthropic 'A global workspace in language models', Jul 2026).
Beyond the logit-lens primitive. Implements the real machinery to identify & score a model's reasoning
'global workspace', as a DATA-FREE genetic-merge fitness:
1. FUTURE-INFLUENCE JACOBIAN (the actual J-lens signal, not next-token logit-lens):
G_l = d(total future NLL)/d(hidden_l) [seq,hid]. Row i = the direction in which position i's
activation steers ALL future outputs (causal). This is "the pattern that makes the model likely to
say things later" — the workspace read/write signal.
2. J-SPACE SUBSPACE via SVD of G_l per layer:
- energy_conc : fraction of future-influence energy in the top-k singular directions.
- eff_rank : exp(entropy of normalized singular values) — a LOW effective rank = a small,
coherent workspace (<10% signature). Reported as frac = eff_rank/hidden.
- The top singular vectors ARE the J-space directions at that layer.
3. PLANNING via the lens: how EARLY the model resolves future tokens (front-loaded competence),
base=layer1 (skip embeddings). A rich workspace reasons in mid layers, not just at the end.
4. CAUSAL INTERVENTION: project the J-space subspace OUT at a mid layer (hook) and measure the
reasoning-NLL increase vs a random-subspace-of-equal-rank control. If ablating the workspace hurts
reasoning MORE than a random subspace, the identified subspace is causally the reasoning substrate.
5. Composite FITNESS = f(front_load, workspace concentration, causal necessity). All data-free
(fixed reasoning probe set). CPU / float32.
"""
import sys, math, torch
from transformers import AutoModelForCausalLM, AutoTokenizer
MODEL = "/Users/kikocisneros/coco_ppl/attn_longctx/model"; DEV = "cpu"
tok = AutoTokenizer.from_pretrained(MODEL)
def load(): return AutoModelForCausalLM.from_pretrained(MODEL, dtype=torch.float32).to(DEV).eval()
PROBES = [
"Q: If a train goes 60 km in 1 hour, how far in 3 hours? 60 times 3 equals",
"Q: Ana has 5 apples, buys 7 more, gives 3 away. 5 plus 7 is 12, minus 3 is",
"Q: A spider has 8 legs. How many legs do 3 spiders have? 8 times 3 is",
"The opposite of hot is cold. The opposite of up is down. The opposite of fast is",
"Paris is to France as Rome is to",
]
# ── hooks to capture per-layer hidden states with grad, and to intervene ──
class Tap:
def __init__(self, model):
self.model = model; self.L = model.config.num_hidden_layers
self.h = {}; self.handles = []; self.intervene = None
def __enter__(self):
for l, lyr in enumerate(self.model.model.layers):
self.handles.append(lyr.register_forward_hook(self._mk(l)))
return self
def _mk(self, l):
def hook(m, i, o):
hs = o[0] if isinstance(o, tuple) else o
if self.intervene and self.intervene[0] == l: # project OUT a subspace at this layer
Q = self.intervene[1] # [hid,k] orthonormal
hs2 = hs - (hs @ Q) @ Q.transpose(-1, -2)
hs = hs2
return (hs2,) + o[1:] if isinstance(o, tuple) else hs2
if hs.requires_grad: # skip under torch.no_grad (reasoning_nll)
hs.retain_grad(); self.h[l] = hs
return hook
def __exit__(self, *a):
for h in self.handles: h.remove()
def influence_jacobian(model, ids):
"""G_l = d(total next-token NLL)/d(hidden_l) for each layer -> {l: [seq,hid]} (future-influence dirs)."""
with Tap(model) as tap:
out = model(ids)
loss = torch.nn.functional.cross_entropy(out.logits[0, :-1], ids[0, 1:], reduction="sum")
loss.backward()
G = {l: tap.h[l].grad[0].detach().clone() for l in range(tap.L) if tap.h[l].grad is not None}
model.zero_grad(set_to_none=True)
return G
def subspace_stats(G_l, k=8):
"""SVD of the future-influence matrix [seq,hid] -> workspace concentration + effective rank + top dirs."""
U, S, Vh = torch.linalg.svd(G_l.float(), full_matrices=False) # V rows = influence directions
s = S / (S.sum() + 1e-9)
energy_topk = s[:k].sum().item()
ent = -(s * (s + 1e-12).log()).sum().item()
eff_rank = math.exp(ent)
return {"energy_topk": energy_topk, "eff_rank_frac": eff_rank / G_l.shape[1],
"dirs": Vh[:k].transpose(0, 1)} # [hid,k] top-k directions
def frontload_and_final(model, ids):
L = model.config.num_hidden_layers; norm, head = model.model.norm, model.lm_head
with torch.no_grad():
hs = model(ids, output_hidden_states=True).hidden_states
tgt = ids[0, 1:]; lp = []
for l in range(L+1):
ll = head(norm(hs[l][0][:-1])).float()
lp.append(torch.log_softmax(ll, -1).gather(1, tgt.unsqueeze(1)).squeeze(1).mean().item())
base, final = lp[1], lp[-1]
c = [max(0., min(1.2, (v - base) / (final - base + 1e-6))) for v in lp]
return sum(c[1:]) / L, final # frontload AUC, final competence
@torch.no_grad()
def reasoning_nll(model, ids, intervene=None):
with Tap(model) as tap:
tap.intervene = intervene
out = model(ids)
return torch.nn.functional.cross_entropy(out.logits[0, :-1], ids[0, 1:]).item()
def causal_necessity(model, ids, layer, k=8):
"""Ablate the J-space subspace at `layer` vs a random subspace of equal rank -> reasoning-NLL delta."""
G = influence_jacobian(model, ids)
if layer not in G: return 0.0
Q = subspace_stats(G[layer], k)["dirs"] # [hid,k] workspace dirs
Qr, _ = torch.linalg.qr(torch.randn_like(Q)) # random orthonormal control
base = reasoning_nll(model, ids)
js = reasoning_nll(model, ids, intervene=(layer, Q))
rnd = reasoning_nll(model, ids, intervene=(layer, Qr))
return (js - base) - (rnd - base) # extra damage from ablating the workspace
def fitness(model, verbose=False):
L = model.config.num_hidden_layers; mid = L // 2
fl, fc, et, er, cn = [], [], [], [], []
for p in PROBES:
ids = tok(p, return_tensors="pt").input_ids.to(DEV)
a, b = frontload_and_final(model, ids); fl.append(a); fc.append(b)
G = influence_jacobian(model, ids)
st = subspace_stats(G[mid]); et.append(st["energy_topk"]); er.append(st["eff_rank_frac"])
cn.append(causal_necessity(model, ids, mid))
r = {"frontload": sum(fl)/len(fl), "final_comp": sum(fc)/len(fc),
"ws_energy_topk": sum(et)/len(et), "ws_effrank_frac": sum(er)/len(er),
"causal_necessity": sum(cn)/len(cn)}
# composite: reward front-loading + a concentrated workspace (high top-k energy, low eff-rank) + causal necessity
r["JSPACE_FITNESS"] = (r["frontload"] + r["ws_energy_topk"] - r["ws_effrank_frac"]
+ 0.1 * r["causal_necessity"] + 0.1 * r["final_comp"])
if verbose:
for k, v in r.items(): print(f" {k:18s} = {v:+.4f}")
return r
if __name__ == "__main__":
print("=== J-SPACE (advanced) on clean 0.5B ==="); fitness(load(), verbose=True)
print("JSPACE_ADV_DONE")
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