Pith Number

pith:RQPBCQ34

pith:1993:RQPBCQ34ZWC62LOQVWRWUIPW7O

not attested not anchored not stored refs pending

A variety with solvable, but not uniformly solvable, word problem

Alan H. Mekler, Evelyn Nelson, Saharon Shelah

arxiv:math/9301203 v1 · 1993-01-15 · math.LO · math.RA

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{RQPBCQ34ZWC62LOQVWRWUIPW7O}

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	2026-05-18T01:05:52.402794Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

8c1e11437ccd85ed2dd0ada36a21f6fb9984656d6c60e642d6ba4d46da48e262

Aliases

arxiv: math/9301203 · arxiv_version: math/9301203v1 · doi: 10.48550/arxiv.math/9301203 · pith_short_12: RQPBCQ34ZWC6 · pith_short_16: RQPBCQ34ZWC62LOQ · pith_short_8: RQPBCQ34

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/RQPBCQ34ZWC62LOQVWRWUIPW7O \
  | 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: 8c1e11437ccd85ed2dd0ada36a21f6fb9984656d6c60e642d6ba4d46da48e262

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "4576c270bb59b0a8870d6fc78b1464fd6961fdd26cae75c533ec3052c79bf1df",
    "cross_cats_sorted": [
      "math.RA"
    ],
    "license": "",
    "primary_cat": "math.LO",
    "submitted_at": "1993-01-15T00:00:00Z",
    "title_canon_sha256": "281c6e4c2df9b7b219e340f712bd8e8860c9be8f1c85595e852e868a8c011681"
  },
  "schema_version": "1.0",
  "source": {
    "id": "math/9301203",
    "kind": "arxiv",
    "version": 1
  }
}