Pith Number

pith:ETWRHMQ4

pith:2015:ETWRHMQ4PITFCS3Y34IWP752AY

not attested not anchored not stored refs pending

Which Regular Expression Patterns are Hard to Match?

Arturs Backurs, Piotr Indyk

arxiv:1511.07070 v2 · 2015-11-22 · cs.CC · 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{ETWRHMQ4PITFCS3Y34IWP752AY}

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	2026-05-18T01:03:50.848960Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

24ed13b21c7a26514b78df1167ffba061497e4d00606483abfd951924d5955bc

Aliases

arxiv: 1511.07070 · arxiv_version: 1511.07070v2 · doi: 10.48550/arxiv.1511.07070 · pith_short_12: ETWRHMQ4PITF · pith_short_16: ETWRHMQ4PITFCS3Y · pith_short_8: ETWRHMQ4

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/ETWRHMQ4PITFCS3Y34IWP752AY \
  | 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: 24ed13b21c7a26514b78df1167ffba061497e4d00606483abfd951924d5955bc

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "a2d3ac6d92582a9954ea438da38e056e6700645d582f6ad82eccae6d5ae07312",
    "cross_cats_sorted": [
      "cs.DS"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.CC",
    "submitted_at": "2015-11-22T21:10:49Z",
    "title_canon_sha256": "41de33dba5d4d3696519f5142b7d38321fa31f342136b016ad800cdb028f66a3"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1511.07070",
    "kind": "arxiv",
    "version": 2
  }
}