Pith Number

pith:NHN35MN7

pith:2015:NHN35MN77JKHDZZIW73NYJHMGR

not attested not anchored not stored refs pending

The MSO+U theory of (N, <) is undecidable

Miko{\l}aj Boja\'nczyk, Pawe{\l} Parys, Szymon Toru\'nczyk

arxiv:1502.04578 v2 · 2015-02-16 · 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{NHN35MN77JKHDZZIW73NYJHMGR}

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	2026-05-18T02:26:58.499772Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

69dbbeb1bffa5471e728b7f6dc24ec344fff533ebd4fe1fbbf477f48f302f095

Aliases

arxiv: 1502.04578 · arxiv_version: 1502.04578v2 · doi: 10.48550/arxiv.1502.04578 · pith_short_12: NHN35MN77JKH · pith_short_16: NHN35MN77JKHDZZI · pith_short_8: NHN35MN7

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/NHN35MN77JKHDZZIW73NYJHMGR \
  | 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: 69dbbeb1bffa5471e728b7f6dc24ec344fff533ebd4fe1fbbf477f48f302f095

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "d7b3377a3823f8dfba44d6b40abd35c7004f1e84f4113cf00c3e63a2a641804c",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.LO",
    "submitted_at": "2015-02-16T15:35:39Z",
    "title_canon_sha256": "ed8de634b2b44b48252636e0200beeb2b9a38631958609fa37a83a6e589fdc28"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1502.04578",
    "kind": "arxiv",
    "version": 2
  }
}