Pith Number

pith:OKOX6BGZ

pith:2026:OKOX6BGZKDROBWQVHJCDC5FOFF

not attested not anchored not stored refs pending

Constraint Satisfaction Problems over Finitely Bounded Homogeneous Structures: a Dichotomy between FO and L-hard

Leonid Dorochko, Micha{\l} Wrona

CSPs over first-order expansions of finitely bounded homogeneous model-complete cores are either first-order definable or L-hard under first-order reduction.

arxiv:2601.22691 v3 · 2026-01-30 · cs.CC · cs.LO

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\pithnumber{OKOX6BGZKDROBWQVHJCDC5FOFF}

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4 Citations open

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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.

Claims

C1strongest claim

CSPs over first-order expansions of finitely bounded homogeneous model-complete cores are either first-order definable (and hence in non-uniform AC0) or L-hard under first-order reduction.

C2weakest assumption

The structures under consideration are model-complete cores and the new proof of the Larose-Tesson theorem for finite structures lifts directly to the infinite case without additional hidden assumptions on the reducts.

C3one line summary

CSPs over FO expansions of finitely bounded homogeneous model-complete cores are either FO-definable (in non-uniform AC0) or L-hard under FO reductions.

Receipt and verification

First computed	2026-07-16T00:21:44.897051Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

729d7f04d950e2e0da153a443174ae294f01f826dcaab1b76ac2a6ee5f2f8e8f

Aliases

arxiv: 2601.22691 · arxiv_version: 2601.22691v3 · doi: 10.48550/arxiv.2601.22691 · pith_short_12: OKOX6BGZKDRO · pith_short_16: OKOX6BGZKDROBWQV · pith_short_8: OKOX6BGZ

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/OKOX6BGZKDROBWQVHJCDC5FOFF \
  | 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: 729d7f04d950e2e0da153a443174ae294f01f826dcaab1b76ac2a6ee5f2f8e8f

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "ca85770be484f9c02dbd1562c5e78dcea9f6340ece59a088f8f46207698ade2c",
    "cross_cats_sorted": [
      "cs.LO"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "cs.CC",
    "submitted_at": "2026-01-30T08:11:38Z",
    "title_canon_sha256": "a7223a041d78f2a8545026edc9c7cf9469dca91531babdd77c18388d0d857691"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2601.22691",
    "kind": "arxiv",
    "version": 3
  }
}