Pith Number

pith:VIAW4PMP

pith:2026:VIAW4PMPOHYVVJYYTWBK3JH7F5

not attested not anchored not stored refs pending

2.5-D Decomposition for LLM-Based Spatial Construction

Li-Jen Chen, Paul Whitten, Sharath Baddam

A 2.5-D decomposition lets LLMs build structures from language instructions by planning only the horizontal plane while a deterministic executor computes vertical placements from column occupancy.

arxiv:2605.07066 v2 · 2026-05-08 · cs.AI

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\usepackage{pith}
\pithnumber{VIAW4PMPOHYVVJYYTWBK3JH7F5}

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Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

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

On the Build What I Mean benchmark (160 rounds), GPT-4o-mini with this pipeline achieves 94.6% mean structural accuracy across 12 independent runs, within 3.0 percentage points of the 97.6% ceiling imposed by architect-agent errors that no builder-side improvement can address. This outperforms both GPT-4o at 90.3% and the best competing system at 76.3%.

C2weakest assumption

That vertical block placements are fully and correctly determined solely by column occupancy without requiring additional spatial reasoning or handling complex inter-block dependencies beyond simple stacking.

C3one line summary

2.5-D decomposition lets LLMs achieve 94.6% structural accuracy on a building benchmark by handling only horizontal planning while a symbolic system manages vertical placements from occupancy.

Receipt and verification

First computed	2026-05-20T01:06:09.882679Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

aa016e3d8f71f15aa7189d82ada4ff2f70492113faeb61831650fef2c777bd7e

Aliases

arxiv: 2605.07066 · arxiv_version: 2605.07066v2 · doi: 10.48550/arxiv.2605.07066 · pith_short_12: VIAW4PMPOHYV · pith_short_16: VIAW4PMPOHYVVJYY · pith_short_8: VIAW4PMP

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/VIAW4PMPOHYVVJYYTWBK3JH7F5 \
  | 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: aa016e3d8f71f15aa7189d82ada4ff2f70492113faeb61831650fef2c777bd7e

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "1542e9f7a33f4ca5981b4c90c26d920c3faa5a066e154bd717d7e16a69cc286a",
    "cross_cats_sorted": [],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "cs.AI",
    "submitted_at": "2026-05-08T00:17:33Z",
    "title_canon_sha256": "5b529320c8728de9af002b36202f427c6b3259fc19b53fdeb0e86748b126dabe"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2605.07066",
    "kind": "arxiv",
    "version": 2
  }
}