Pith Number

pith:XIL6WW2H

pith:2009:XIL6WW2HTT2XSQGSBKP2UKBEHU

not attested not anchored not stored refs pending

On the utility of Robinson-Amitsur ultrafilters

Pasha Zusmanovich

arxiv:0911.5414 v8 · 2009-11-28 · math.RA · math.GR · math.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{XIL6WW2HTT2XSQGSBKP2UKBEHU}

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	2026-05-18T01:08:27.733954Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

ba17eb5b479cf57940d20a9faa28243d1565598a2c84eb97f28e0ff781d6d8c4

Aliases

arxiv: 0911.5414 · arxiv_version: 0911.5414v8 · doi: 10.48550/arxiv.0911.5414 · pith_short_12: XIL6WW2HTT2X · pith_short_16: XIL6WW2HTT2XSQGS · pith_short_8: XIL6WW2H

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/XIL6WW2HTT2XSQGSBKP2UKBEHU \
  | 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: ba17eb5b479cf57940d20a9faa28243d1565598a2c84eb97f28e0ff781d6d8c4

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "f9695d268ce195a010f9b0a1878a2fe5299b291cc9c3eded231f199eaaa601ff",
    "cross_cats_sorted": [
      "math.GR",
      "math.LO"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.RA",
    "submitted_at": "2009-11-28T18:57:04Z",
    "title_canon_sha256": "0e344aec7f54a5c89e3bb24ee60c95d18b6f8796b93387536b407e0fe8337838"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0911.5414",
    "kind": "arxiv",
    "version": 8
  }
}