Pith Number

pith:YPQWHHCM

pith:2007:YPQWHHCMXSXLFOFVWBITZIG4HV

not attested not anchored not stored refs pending

Freeness of Conic-Line Arrangements in $\mathbb P^2$

Hal Schenck, Stefan O. Tohaneanu

arxiv:0709.1890 v1 · 2007-09-12 · math.AC · 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{YPQWHHCMXSXLFOFVWBITZIG4HV}

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	2026-05-18T04:03:44.169987Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

c3e1639c4cbcaeb2b8b5b0513ca0dc3d5ce856066bec5c25a537292fd9a843de

Aliases

arxiv: 0709.1890 · arxiv_version: 0709.1890v1 · doi: 10.48550/arxiv.0709.1890 · pith_short_12: YPQWHHCMXSXL · pith_short_16: YPQWHHCMXSXLFOFV · pith_short_8: YPQWHHCM

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/YPQWHHCMXSXLFOFVWBITZIG4HV \
  | 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: c3e1639c4cbcaeb2b8b5b0513ca0dc3d5ce856066bec5c25a537292fd9a843de

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "6c5a13018ecc6072e80d13fdfd95de0ba54e0c595ac3130203db841e77f92550",
    "cross_cats_sorted": [
      "math.CO"
    ],
    "license": "",
    "primary_cat": "math.AC",
    "submitted_at": "2007-09-12T14:40:58Z",
    "title_canon_sha256": "221853d0a3b6b9dcf34ffe856f70fb2331bafceee6fc88b681acfb39cd8d2476"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0709.1890",
    "kind": "arxiv",
    "version": 1
  }
}