Lean verification record

Checked Artifact: Kruskal–Katona 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: Finset.kruskal_katona
Module: Mathlib.Combinatorics.SetFamily.KruskalKatona
Source file checked: Mathlib/Combinatorics/SetFamily/KruskalKatona.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 page indexes Mathlib’s colex-initial-segment form of the Kruskal–Katona theorem for finite families of subsets of Fin n. The comparison family 𝒜 is r-uniform, 𝒞 is a colex initial segment of the r-subsets, and #𝒞 may be smaller than #𝒜. The selected endpoint compares only the cardinalities of their immediate one-element-deletion shadows. It is not the later iterated-shadow theorem, the Lovász/binomial formulation, an equality-case classification, a uniqueness theorem, or an algorithm.

This checker record does not establish novelty, transfer a historical acceptance decision, or authorize publication.