Pith Number

pith:CEXDWRGZ

pith:2019:CEXDWRGZYCKPKONJ4O5FOUSCJY

not attested not anchored not stored refs pending

On Double Danielewski Surfaces and the Cancellation Problem

Neena Gupta, Sourav Sen

arxiv:1908.03403 v1 · 2019-08-09 · math.AC · math.AG

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{CEXDWRGZYCKPKONJ4O5FOUSCJY}

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	2026-07-04T23:52:39.736099Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

112e3b44d9c094f539a9e3ba5752424e2a94af5b6b7ed451c6870d44e7c9ec70

Aliases

arxiv: 1908.03403 · arxiv_version: 1908.03403v1 · doi: 10.48550/arxiv.1908.03403 · pith_short_12: CEXDWRGZYCKP · pith_short_16: CEXDWRGZYCKPKONJ · pith_short_8: CEXDWRGZ

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/CEXDWRGZYCKPKONJ4O5FOUSCJY \
  | 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: 112e3b44d9c094f539a9e3ba5752424e2a94af5b6b7ed451c6870d44e7c9ec70

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "007e42f708c16e711af94aeddef92f16749c52617a2804ada2021d3522395bcb",
    "cross_cats_sorted": [
      "math.AG"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AC",
    "submitted_at": "2019-08-09T10:44:01Z",
    "title_canon_sha256": "dcbceca79cbfbb05cd94ba11a75676285abdcf77cb05564c145588e0c0d5ac55"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1908.03403",
    "kind": "arxiv",
    "version": 1
  }
}