Pith Number

pith:2JNCKFWJ

pith:2013:2JNCKFWJDHU6SR2R3VNRD2LBY5

not attested not anchored not stored refs pending

The freeness problem over matrix semigroups and bounded languages

\'Emilie Charlier, Juha Honkala

arxiv:1304.1637 v1 · 2013-04-05 · cs.DM · 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{2JNCKFWJDHU6SR2R3VNRD2LBY5}

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	2026-05-18T03:28:55.107744Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

d25a2516c919e9e94751dd5b11e961c75752f05ea8345993d7e98e487f4ae02c

Aliases

arxiv: 1304.1637 · arxiv_version: 1304.1637v1 · doi: 10.48550/arxiv.1304.1637 · pith_short_12: 2JNCKFWJDHU6 · pith_short_16: 2JNCKFWJDHU6SR2R · pith_short_8: 2JNCKFWJ

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/2JNCKFWJDHU6SR2R3VNRD2LBY5 \
  | 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: d25a2516c919e9e94751dd5b11e961c75752f05ea8345993d7e98e487f4ae02c

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "661786c4b6ca7f62ebcc5fc3be2e4d970522457929087d3debe591758e6d2ad0",
    "cross_cats_sorted": [
      "math.CO"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.DM",
    "submitted_at": "2013-04-05T08:26:12Z",
    "title_canon_sha256": "1e2712208333b85168829aa3658477d2c11b31f2b44c90eb19fdda19df84a240"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1304.1637",
    "kind": "arxiv",
    "version": 1
  }
}