Pith Number

pith:XLZRZ7JQ

pith:2013:XLZRZ7JQ4FH3U37KHNXJADPF4L

not attested not anchored not stored refs pending

Quasi-projective relation algebras and directed cylindric algebras are categorially equivalent

Tarek Sayed Ahmed

arxiv:1304.0761 v1 · 2013-04-02 · 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{XLZRZ7JQ4FH3U37KHNXJADPF4L}

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	2026-05-18T03:29:06.141480Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

baf31cfd30e14fba6fea3b6e900de5e2d4c15ea55e7a93769c60c90c2927269b

Aliases

arxiv: 1304.0761 · arxiv_version: 1304.0761v1 · doi: 10.48550/arxiv.1304.0761 · pith_short_12: XLZRZ7JQ4FH3 · pith_short_16: XLZRZ7JQ4FH3U37K · pith_short_8: XLZRZ7JQ

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/XLZRZ7JQ4FH3U37KHNXJADPF4L \
  | 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: baf31cfd30e14fba6fea3b6e900de5e2d4c15ea55e7a93769c60c90c2927269b

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "bb35964e9dc4a6850a0436c00fb138fd09bc4033897d414b6ebb739a7bec39d1",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.LO",
    "submitted_at": "2013-04-02T18:42:11Z",
    "title_canon_sha256": "71bb7f4b28b3f8062b4b01c5a95a3e34b6446e1c093fe247b73d3021b8763106"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1304.0761",
    "kind": "arxiv",
    "version": 1
  }
}