Pith Number

pith:ZPCXCZ5M

pith:2013:ZPCXCZ5M44N3BX445V4WPD7KE5

not attested not anchored not stored refs pending

On Leonardo da Vinci's proof of the Theorem of Pythagoras

Franz Lemmermeyer

arxiv:1311.0816 v2 · 2013-11-04 · math.HO

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{ZPCXCZ5M44N3BX445V4WPD7KE5}

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	2026-05-18T03:02:17.230393Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

cbc57167ace71bb0df9ced79678fea27797c83abfb0f092ef2c53abda916567a

Aliases

arxiv: 1311.0816 · arxiv_version: 1311.0816v2 · doi: 10.48550/arxiv.1311.0816 · pith_short_12: ZPCXCZ5M44N3 · pith_short_16: ZPCXCZ5M44N3BX44 · pith_short_8: ZPCXCZ5M

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/ZPCXCZ5M44N3BX445V4WPD7KE5 \
  | 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: cbc57167ace71bb0df9ced79678fea27797c83abfb0f092ef2c53abda916567a

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "7bb0daf9a4ef6b05bfe8ecb73699a27a03922c85d653ab8c9ff8dae20f3cd8f9",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.HO",
    "submitted_at": "2013-11-04T19:15:41Z",
    "title_canon_sha256": "7e80f753e38afcf7f2994d7306d16371a3d736908d026d9cd31e6a60918a2592"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1311.0816",
    "kind": "arxiv",
    "version": 2
  }
}