Pith Number

pith:JW6ERYEP

pith:2018:JW6ERYEP2TFO2A6N4YSMXYNMBI

not attested not anchored not stored refs pending

Groups whose word problems are not semilinear

Robert H. Gilman, Robert P. Kropholler, Saul Schleimer

arxiv:1804.09609 v1 · 2018-04-25 · math.GR

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{JW6ERYEP2TFO2A6N4YSMXYNMBI}

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	2026-05-18T00:17:31.262096Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

4dbc48e08fd4caed03cde624cbe1ac0a03dd7d9477f5bdc04f61750ba5a9a101

Aliases

arxiv: 1804.09609 · arxiv_version: 1804.09609v1 · doi: 10.48550/arxiv.1804.09609 · pith_short_12: JW6ERYEP2TFO · pith_short_16: JW6ERYEP2TFO2A6N · pith_short_8: JW6ERYEP

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/JW6ERYEP2TFO2A6N4YSMXYNMBI \
  | 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: 4dbc48e08fd4caed03cde624cbe1ac0a03dd7d9477f5bdc04f61750ba5a9a101

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "281c200f25f4920953198a2c8506fd8a4634ce281a1440f6058e7e4bcd4f2318",
    "cross_cats_sorted": [],
    "license": "http://creativecommons.org/publicdomain/zero/1.0/",
    "primary_cat": "math.GR",
    "submitted_at": "2018-04-25T14:52:09Z",
    "title_canon_sha256": "a4240d896eef0b999a0ccb9a7838eb9410a9969526aad276ef59e1b33ba831ce"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1804.09609",
    "kind": "arxiv",
    "version": 1
  }
}