Lean verification record
Checked Artifact: Banach Fixed-Point Theorem (mathlib)
Proof Atlas collected build, no-sorry, axiom, and clean-source evidence directly from the pinned upstream declaration.
Verification result
The recorded Lean checks passed
- Build replaypassed with retained transcript
- Unfinished stepsNone found
- Source identityPinned commit and file recorded
- Dependency profileAxiom closure recorded
Reproducibility details
What the checker recorded
- Declaration checked
ContractingWith.exists_fixedPoint- Module
Mathlib.Topology.MetricSpace.Contracting- Source file checked
Mathlib/Topology/MetricSpace/Contracting.lean- Package commit
5e932f97dd25535344f80f9dd8da3aab83df0fe6- Build transcript
- passed · retained with this record
- Unfinished proof steps
- None found by the recorded no-sorry scan
- Axiom closure
- Classical.choice, Quot.sound, propext
- Collection provenance
- Clean source state recorded
ProofAtlas record
What has been checked
Upstream indexedPinned source bytes verified locally
Locally reproducedExact upstream declaration replayed
Reviewed pageCurrent public presentation reviewed
Accepted Atlas resultNot recorded for the preferred artifact
Mathlib is the source of the theorem; the local Lean replay and page review are separate.
Evidence boundary
Exact formal statement only
This target indexes Mathlib's complete extended-metric-space contraction theorem from a starting point with finite first displacement. It gives a fixed point, convergence of iterates, and a geometric error bound. Uniqueness is a companion theorem, not part of this selected declaration.
This checker record does not establish novelty, transfer a historical acceptance decision, or authorize publication.