Pith Number

pith:7U4SHGHZ

pith:2018:7U4SHGHZWL3KYBQSL2H4VRPFZW

not attested not anchored not stored refs pending

Vertex Covers Revisited: Indirect Certificates and FPT Algorithms

Leizhen Cai

arxiv:1807.11339 v1 · 2018-07-30 · cs.DS

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{7U4SHGHZWL3KYBQSL2H4VRPFZW}

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	2026-05-18T00:09:32.177574Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

fd392398f9b2f6ac06125e8fcac5e5cd96b4638a96a5056108551c2b15346e2f

Aliases

arxiv: 1807.11339 · arxiv_version: 1807.11339v1 · doi: 10.48550/arxiv.1807.11339 · pith_short_12: 7U4SHGHZWL3K · pith_short_16: 7U4SHGHZWL3KYBQS · pith_short_8: 7U4SHGHZ

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/7U4SHGHZWL3KYBQSL2H4VRPFZW \
  | 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: fd392398f9b2f6ac06125e8fcac5e5cd96b4638a96a5056108551c2b15346e2f

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "109dd37db5f3e1956f86eb993a33e71fcade8cb3952d7bca96e847be7fed1879",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.DS",
    "submitted_at": "2018-07-30T13:27:36Z",
    "title_canon_sha256": "f09c2573a39e39445681599b536d4fbbd7ea3f8fe2a0504d7ac3cfdca1f215b1"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1807.11339",
    "kind": "arxiv",
    "version": 1
  }
}