Pith Number

pith:37YIWGVL

pith:2019:37YIWGVLSVPCZ7SQPK255KDLIE

not attested not anchored not stored refs pending

On the 4-color theorem for signed graphs

Franti\v{s}ek Kardo\v{s}, Jonathan Narboni

arxiv:1906.05638 v1 · 2019-06-13 · 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{37YIWGVLSVPCZ7SQPK255KDLIE}

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	2026-05-17T23:43:24.760829Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

dff08b1aab955e2cfe507ab5dea86b412361814862a4f226b5dd4f892d2a638f

Aliases

arxiv: 1906.05638 · arxiv_version: 1906.05638v1 · doi: 10.48550/arxiv.1906.05638 · pith_short_12: 37YIWGVLSVPC · pith_short_16: 37YIWGVLSVPCZ7SQ · pith_short_8: 37YIWGVL

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/37YIWGVLSVPCZ7SQPK255KDLIE \
  | 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: dff08b1aab955e2cfe507ab5dea86b412361814862a4f226b5dd4f892d2a638f

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "d7ac0384be93eaed72dc22aa03279fb0d244fabd45fa1df7bb9d03f7099b2b33",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.CO",
    "submitted_at": "2019-06-13T12:50:27Z",
    "title_canon_sha256": "40d01958c011bd118c325ba237ab3018a4849b4160d553405297d958796e7541"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1906.05638",
    "kind": "arxiv",
    "version": 1
  }
}