TheoremDB
R1820formalizationStatus: pending verificationEvidence: ReportedLean: kernel unchecked

[#R1820] Pinned Lean proof in cdc-lean

View verificationOpen source ↗

1Summary

A public Lean 4.31.0 development proves the cycle-double-cover endpoint without project-specific axioms; controlled TheoremDB verification is still pending.

The endpoint `CDCLean.cycleDoubleCover_of_bridgeless` takes a finite edge-labelled loopless multigraph and a proof of its cut-based bridgeless predicate, and returns a nonempty cycle double cover. Parallel edges, disconnected graphs, and edgeless graphs are covered. The pinned repository records a successful full build, a source scan with no `sorry`, `admit`, `native_decide`, custom `axiom`, `opaque`, or `unsafe`, and an axiom report containing only `propext`, `Classical.choice`, and `Quot.sound`. Those are upstream results. TheoremDB has pinned the source and dependency world but has not yet executed this repository inside its controlled verifier, so the formalization remains unverified here.

Reported evidence. Recorded scope: the exact finite loopless multigraph theorem represented by CDCLean.FiniteGraph.

2Verification

Verification material: partial

Part of the replay path is recorded. Check the missing fields before comparing a new run.

lake build CDCLean && lake env lean CDCLean/Audit.lean
Entry point
CDCLean.cycleDoubleCover_of_bridgeless
Runtime
Lean 4.31.0 with mathlib4@9a9483a92959bc92bd6a60176dd1fe597298c1f8

Verification source: github.com ↗, CDCLean/Main.lean theorem CDCLean.cycleDoubleCover_of_bridgeless and VERIFICATION.md

Expected output

{
  "upstream_expected_exit_code": 0,
  "upstream_axiom_audit": [
    "propext",
    "Classical.choice",
    "Quot.sound"
  ],
  "theoremdb_controlled_verification": "pending"
}

3Formal statement

leanlean-4.31.0/mathlib4@9a9483a92959bc92bd6a60176dd1fe597298c1f8+cdc-lean@577e9d9ea326d520f80672ee69b830bf1d513df5
theorem CDCLean.cycleDoubleCover_of_bridgeless
    {V E : Type u} [Fintype V] [Fintype E] [DecidableEq V] [DecidableEq E]
    (G : FiniteGraph V E) (hb : G.Bridgeless) :
    Nonempty G.CycleDoubleCover

4What was measured

Source url
https://github.com/openai/cdc-lean/blob/577e9d9ea326d520f80672ee69b830bf1d513df5/CDCLean/Main.lean
Source revision
577e9d9ea326d520f80672ee69b830bf1d513df5
Source sha256
868348894074fa6d695a4483f600a8b779b478edf49d72b3d75a76f06f319482
Network requirements
none after the pinned Lake dependencies are available
Verification statement
theorem CDCLean.cycleDoubleCover_of_bridgeless {V E : Type u} [Fintype V] [Fintype E] [DecidableEq V] [DecidableEq E] (G : FiniteGraph V E) (hb : G.Bridgeless) : Nonempty G.CycleDoubleCover
Statement fidelity
The endpoint matches the packet's finite loopless multigraph convention, admits parallel edges, assumes no connectedness, and represents cycles as inclusion-minimal nonempty even edge sets.
Upstream verification record sha256
9f860b77f436a66046a0911dbf3775d83fa4e0aabc60f77c2ad6516044a0f364

5How it connects

Formalizes

Recorded for

6Agent packet

A compact handoff with the evidence boundary, replay manifest, and relation pointers.

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R1820",
  "content_hash": null,
  "slug": "cdc-formalization-upstream-lean-v1",
  "type": "formalization",
  "title": "Pinned Lean proof in cdc-lean",
  "summary": "A public Lean 4.31.0 development proves the cycle-double-cover endpoint without project-specific axioms; controlled TheoremDB verification is still pending.",
  "relevance": "This is a complete public formal proof of the canonical target in a pinned Lean world, awaiting replay by TheoremDB's verifier.",
  "relevance_source": "recorded",
  "body": "The endpoint `CDCLean.cycleDoubleCover_of_bridgeless` takes a finite edge-labelled loopless multigraph and a proof of its cut-based bridgeless predicate, and returns a nonempty cycle double cover. Parallel edges, disconnected graphs, and edgeless graphs are covered. The pinned repository records a successful full build, a source scan with no `sorry`, `admit`, `native_decide`, custom `axiom`, `opaque`, or `unsafe`, and an axiom report containing only `propext`, `Classical.choice`, and `Quot.sound`. Those are upstream results. TheoremDB has pinned the source and dependency world but has not yet executed this repository inside its controlled verifier, so the formalization remains unverified here.",
  "status": "pending_verification",
  "evidence_grade": "unverified_formalization",
  "scope": {
    "kind": "universal",
    "statement": "the exact finite loopless multigraph theorem represented by CDCLean.FiniteGraph"
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "partial",
    "kind": "lean4_formalization_source",
    "command": "lake build CDCLean && lake env lean CDCLean/Audit.lean",
    "entrypoint": "CDCLean.cycleDoubleCover_of_bridgeless",
    "runtime": "Lean 4.31.0 with mathlib4@9a9483a92959bc92bd6a60176dd1fe597298c1f8",
    "citation": {
      "url": "https://github.com/openai/cdc-lean/tree/577e9d9ea326d520f80672ee69b830bf1d513df5",
      "locator": "CDCLean/Main.lean theorem CDCLean.cycleDoubleCover_of_bridgeless and VERIFICATION.md"
    },
    "outputs": {
      "upstream_expected_exit_code": 0,
      "upstream_axiom_audit": [
        "propext",
        "Classical.choice",
        "Quot.sound"
      ],
      "theoremdb_controlled_verification": "pending"
    },
    "missing": [
      "source"
    ]
  },
  "formal_statement": "theorem CDCLean.cycleDoubleCover_of_bridgeless\n    {V E : Type u} [Fintype V] [Fintype E] [DecidableEq V] [DecidableEq E]\n    (G : FiniteGraph V E) (hb : G.Bridgeless) :\n    Nonempty G.CycleDoubleCover",
  "source": {
    "url": "https://github.com/openai/cdc-lean/tree/577e9d9ea326d520f80672ee69b830bf1d513df5",
    "locator": "CDCLean/Main.lean theorem CDCLean.cycleDoubleCover_of_bridgeless and VERIFICATION.md"
  },
  "relations": [
    {
      "slug": "R1819",
      "title": "Every finite bridgeless graph has a cycle double cover",
      "object_type": "claim",
      "relation": "formalizes",
      "direction": "outgoing"
    },
    {
      "slug": "cycle-double-cover-conjecture",
      "title": "cycle double cover conjecture",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details
Project
cycle-double-cover-conjecture
Locator
CDCLean/Main.lean theorem CDCLean.cycleDoubleCover_of_bridgeless and VERIFICATION.md
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-08-01
Public record
R1820
Stable alias
cdc-formalization-upstream-lean-v1
Projection
Reproduction fields are derived from the immutable record.

A machine-checkable rendering of a statement, with the world it was written against.

Report a problem

Your ChatGPT account

Opening ChatGPT

ChatGPT is opening in a new tab.