Pith Number

pith:6M6GD7VD

pith:2025:6M6GD7VD5G3YLJT6MSXERFVDKI

not attested not anchored not stored refs resolved

When Diffusion Breaks Constraints: Sequential Autoregressive Generation with RL and MCTS

Boye Niu, David Hsu, Harold Soh, Wee Sun Lee, Zirui Zhao

Diffusion models fail to satisfy strict geometric constraints in planning tasks because continuous density matching cannot target low-dimensional feasible regions, while reformulating generation as sequential discrete choices with RL and M-

arxiv:2512.01242 v3 · 2025-12-01 · cs.CV · cs.AI · cs.CL

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\usepackage{pith}
\pithnumber{6M6GD7VD5G3YLJT6MSXERFVDKI}

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3 Author claim open · sign in to claim

4 Citations open

5 Replications open

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The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Claims

C1strongest claim

Overall, the empirical, theoretical, and prior-work evidence points to a structural limitation of continuous density matching on this class of constrained-generation problems, and suggests sequential constraint-aware generation as a promising alternative.

C2weakest assumption

That the failure modes observed in tangram generation from language and the simplified rectangle composition task are representative of the broader class of constrained planning and design tasks mentioned, including engineering inverse design, molecular generation, and multi-robot planning.

C3one line summary

Diffusion models exhibit a structural limitation when generating samples on low-dimensional feasible regions for constrained tasks, and sequential autoregressive generation using RL and MCTS improves constraint satisfaction.

References

58 extracted · 58 resolved · 2 Pith anchors

[1] Shape related constraints aware gen- eration of mechanical designs through deep convolutional gan.arXiv preprint arXiv:2010.11833, 2020 2010

[2] Lexical entrainment without conceptual pacts? revisiting the matching task.Journal of Memory and Language, 114: 104129, 2020 2020

[3] Recognition-by-components: A theory of human image understanding.Psychological Review, 94(2): 115–147, 1987 1987

[4] Ab- stract concepts: External influences, internal constraints, and methodological issues.Psychological Research, 86(8): 2370–2388, 2022 2022

[5] Interac- tion promotes the adaptation of referential conventions to the communicative context.Cognitive science, 43(8):e12780,

Formal links

2 machine-checked theorem links

Receipt and verification

First computed	2026-05-18T03:09:32.924055Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

f33c61fea3e9b785a67e64ae4896a3521a79c5e4b1e62f431599d2212833c4b9

Aliases

arxiv: 2512.01242 · arxiv_version: 2512.01242v3 · doi: 10.48550/arxiv.2512.01242 · pith_short_12: 6M6GD7VD5G3Y · pith_short_16: 6M6GD7VD5G3YLJT6 · pith_short_8: 6M6GD7VD

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/6M6GD7VD5G3YLJT6MSXERFVDKI \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: f33c61fea3e9b785a67e64ae4896a3521a79c5e4b1e62f431599d2212833c4b9

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "eb931f34e2bbcfa6c060e198ba433d82a3a4f392d989f11a1a608b3d34f17d16",
    "cross_cats_sorted": [
      "cs.AI",
      "cs.CL"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "cs.CV",
    "submitted_at": "2025-12-01T03:38:44Z",
    "title_canon_sha256": "1ceea254e081438fe6352f9c9baff7939cc5b472ceb099fd6d34850737767a8c"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2512.01242",
    "kind": "arxiv",
    "version": 3
  }
}