Pith Number

pith:XRP4P4GZ

pith:2008:XRP4P4GZPVQIEHIVRMWRLTPAIT

not attested not anchored not stored refs pending

The Wadge Hierarchy of Deterministic Tree Languages

Filip Murlak

arxiv:0812.1729 v2 · 2008-12-09 · cs.LO

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{XRP4P4GZPVQIEHIVRMWRLTPAIT}

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	2026-05-18T01:37:40.604661Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

bc5fc7f0d97d60821d158b2d15cde044e019371692bd24b6acc98065edf2e631

Aliases

arxiv: 0812.1729 · arxiv_version: 0812.1729v2 · doi: 10.48550/arxiv.0812.1729 · pith_short_12: XRP4P4GZPVQI · pith_short_16: XRP4P4GZPVQIEHIV · pith_short_8: XRP4P4GZ

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/XRP4P4GZPVQIEHIVRMWRLTPAIT \
  | 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: bc5fc7f0d97d60821d158b2d15cde044e019371692bd24b6acc98065edf2e631

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "466e660094d10e7759b199d176b32e4fe125f683e919d0f1ead0ce5193a509ea",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.LO",
    "submitted_at": "2008-12-09T16:14:05Z",
    "title_canon_sha256": "815a00fa081fafc815a38d2169bab7d721d34fd0be3fad96ae83e2b093a210c2"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0812.1729",
    "kind": "arxiv",
    "version": 2
  }
}