Reproduction tutorial · September 10, 2026

    Independent verification of a published Lean artifact

    These tutorials test the mechanism behind each paper at a practical scale. They do not reproduce frontier-scale headline results unless explicitly stated.

    Source of this tutorial

    This tutorial tests the mechanism behind reviewed development 03 in the immutable briefing of September 10, 2026.

    Scope and limits

    Reproduction level
    artifact verification, not rediscovery
    Claim under test
    whether the published formal artifact builds cleanly offline and whether the machine-checked statement is the statement being claimed.
    Excluded claim
    this tutorial does not reproduce the discovery run, the roughly 10,000 concurrent agents, the 88 hours of discovery plus 17 hours of formalization, or the 130 billion output tokens.
    Reader, effort, and cost
    comfort with Lean and Mathlib; 6 to 12 hours; a workstation with sufficient memory. Near-zero cost beyond compute you already own.
    Prerequisites
    Lean toolchain manager, Git, and an offline build cache.

    Canonical resources

    Project plan

    Independent verification of a published Lean artifact — step and effort summary
    StepStageEffort
    01Pin the canonical repository45 minutes
    02Clean offline build2 to 6 hours
    03Statement audit2 hours
    04Axiom and sorry audit1 hour
    05Report1 hour
    1. 01Pin the canonical repository(45 minutes)

      Clone the canonical repository and record the commit hash, the Lean toolchain version, and the exact Mathlib revision from the lockfile.

    2. 02Clean offline build(2 to 6 hours)

      Build from a clean checkout with the network disabled after dependency fetch. A build that requires unpinned downloads is a finding, not a pass. Artifact: full build log with timings.

    3. 03Statement audit(2 hours)

      Read the top-level theorem statement and every definition it depends on. Confirm the formal statement matches the informal claim, including quantifiers, regularity assumptions, and the meaning of the singularity condition.

    4. 04Axiom and sorry audit(1 hour)

      Print the axiom dependencies of the main theorem and search the tree for sorry, admitted results, and unproven custom axioms. Record anything beyond the standard Mathlib axiom set.

    5. 05Report(1 hour)

      Publish the commit hashes, toolchain versions, build log, axiom list, and a plain-language restatement of exactly what was checked and what was not.

    Controls, failure modes, and safety

    Controlled variables

    repository commit, Lean toolchain, Mathlib revision, build environment, and offline mode.

    Failure modes

    assuming a green build proves the informal claim, missing an added axiom, auditing a statement weaker than the announced result, and unpinned dependencies.

    Safety

    read-only verification of published mathematics. No safety hazard.

    Affected topics

    Back to the September 10, 2026 briefing