Pith Number

pith:46QQTRWF

pith:2009:46QQTRWFHO2CCH22OK65LZRQE5

not attested not anchored not stored refs pending

Menger's and Hurewicz's Problems: Solutions from "The Book" and refinements

Boaz Tsaban

arxiv:0909.5645 v5 · 2009-09-30 · math.GN · math.CO · 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{46QQTRWFHO2CCH22OK65LZRQE5}

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	2026-05-18T00:49:05.085515Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

e7a109c6c53bb4211f5a72bdd5e630277a4b425d99f636ad145f3888a4cb2b80

Aliases

arxiv: 0909.5645 · arxiv_version: 0909.5645v5 · doi: 10.48550/arxiv.0909.5645 · pith_short_12: 46QQTRWFHO2C · pith_short_16: 46QQTRWFHO2CCH22 · pith_short_8: 46QQTRWF

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/46QQTRWFHO2CCH22OK65LZRQE5 \
  | 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: e7a109c6c53bb4211f5a72bdd5e630277a4b425d99f636ad145f3888a4cb2b80

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "d2617fd50100f4fa4def356a6a079daaa0760f3bc5ed9424f74f9ae5205fdeb0",
    "cross_cats_sorted": [
      "math.CO",
      "math.LO"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.GN",
    "submitted_at": "2009-09-30T15:47:12Z",
    "title_canon_sha256": "d4b0fb18fcc3b37372d76c6ad7c8fbb73a889b3115519b73148d3c427c6bd40f"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0909.5645",
    "kind": "arxiv",
    "version": 5
  }
}