Pith Number

pith:QPUGCT6F

pith:2009:QPUGCT6FXMR63DPSD6M2M6EDUK

not attested not anchored not stored refs pending

An obstacle to a decomposition theorem for near-regular matroids

Dillon Mayhew, Geoff Whittle, Stefan H. M. van Zwam

arxiv:0905.3252 v3 · 2009-05-20 · math.CO

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{QPUGCT6FXMR63DPSD6M2M6EDUK}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

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.

Receipt and verification

First computed	2026-05-18T02:24:55.695024Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

83e8614fc5bb23ed8df21f99a67883a28e964623fd31bdea42581881f0349879

Aliases

arxiv: 0905.3252 · arxiv_version: 0905.3252v3 · doi: 10.48550/arxiv.0905.3252 · pith_short_12: QPUGCT6FXMR6 · pith_short_16: QPUGCT6FXMR63DPS · pith_short_8: QPUGCT6F

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/QPUGCT6FXMR63DPSD6M2M6EDUK \
  | 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: 83e8614fc5bb23ed8df21f99a67883a28e964623fd31bdea42581881f0349879

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "fcbdf63c4345e226b868de3beb007a1d20fe8f78b1aba6cc0e711c2c3aec88f0",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.CO",
    "submitted_at": "2009-05-20T09:14:16Z",
    "title_canon_sha256": "e489163aeaf6933100b0380907e75696daef65f05282ded7cdacb3dcc7eb2c2d"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0905.3252",
    "kind": "arxiv",
    "version": 3
  }
}