[#R1820] Pinned Lean proof in cdc-lean
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
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
lean-4.31.0/mathlib4@9a9483a92959bc92bd6a60176dd1fe597298c1f8+cdc-lean@577e9d9ea326d520f80672ee69b830bf1d513df5theorem 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.CycleDoubleCover4What 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
- claim
Recorded for
- problem
6Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"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
- Source
- github.com ↗
- 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.