Pith Number

pith:2X37BSB6

pith:2009:2X37BSB6JOACIX4OPHWJZ6RAG6

not attested not anchored not stored refs pending

The twisted Grassmann graph is the block graph of a design

Akihiro Munemasa, Vladimir D. Tonchev

arxiv:0906.4509 v2 · 2009-06-24 · 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{2X37BSB6JOACIX4OPHWJZ6RAG6}

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	2026-05-18T00:32:31.873493Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

d5f7f0c83e4b80245f8e79ec9cfa2037b45e53f5ec51f9d2912d2fc1ac8a0c11

Aliases

arxiv: 0906.4509 · arxiv_version: 0906.4509v2 · doi: 10.48550/arxiv.0906.4509 · pith_short_12: 2X37BSB6JOAC · pith_short_16: 2X37BSB6JOACIX4O · pith_short_8: 2X37BSB6

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/2X37BSB6JOACIX4OPHWJZ6RAG6 \
  | 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: d5f7f0c83e4b80245f8e79ec9cfa2037b45e53f5ec51f9d2912d2fc1ac8a0c11

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "ddf3bd6f591e7323356796e3c3f4750165ca010c509c1a8507659b3a5f20b1c0",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.CO",
    "submitted_at": "2009-06-24T16:05:21Z",
    "title_canon_sha256": "e462d679a57f2da9674bf79a4368166525b399e439a6786dbb967c63db1be3f6"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0906.4509",
    "kind": "arxiv",
    "version": 2
  }
}