Pith Number

pith:U4CUNY4B

pith:2017:U4CUNY4BEEPYGQNQWVALOTKL47

not attested not anchored not stored refs pending

Undecidability and Finite Automata

Jeffrey Shallit, J\"org Endrullis, Tim Smith

arxiv:1702.01394 v2 · 2017-02-05 · cs.FL

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{U4CUNY4BEEPYGQNQWVALOTKL47}

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	2026-05-18T00:49:50.670057Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

a70546e381211f8341b0b540b74d4be7fba69331fea1a9adf37498a5a1cda132

Aliases

arxiv: 1702.01394 · arxiv_version: 1702.01394v2 · doi: 10.48550/arxiv.1702.01394 · pith_short_12: U4CUNY4BEEPY · pith_short_16: U4CUNY4BEEPYGQNQ · pith_short_8: U4CUNY4B

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/U4CUNY4BEEPYGQNQWVALOTKL47 \
  | 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: a70546e381211f8341b0b540b74d4be7fba69331fea1a9adf37498a5a1cda132

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "66af5e616a52d82b9d67cc58e936b1396c0e495529ca48307301d571033c4a97",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.FL",
    "submitted_at": "2017-02-05T12:37:36Z",
    "title_canon_sha256": "c1c3e0a089bd6dd8829dd2e8bbdf24ce71d52308ad4bdc20ecf33288c2909139"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1702.01394",
    "kind": "arxiv",
    "version": 2
  }
}