This page records how the formalization is checked and what was resolved along the way. The landing pages state the current status; the details and the history live here so they do not crowd out the mathematics.
Every change runs scripts/check_census_and_axioms.py, which applies two gates:
-
Sorry census. The project contains zero
sorry/admittokens. The allowlist of permitted stubs is empty (ALLOWED_STUBS = set()), so any reintroduction fails the build. -
Axiom audit. A fixed list of load-bearing declarations is checked with
#print axioms, and each must depend only onpropext,Classical.choice, andQuot.sound.Note the scope precisely: this gate proves that the audited declarations use no custom axioms. It does not scan every declaration in the repository. The project introduces no custom axioms today, but that is a fact about the current source, not something the gate enforces — which is why the audited list is extended whenever a new load-bearing result lands.
The audited declaration list is maintained in two places that must stay in sync:
scripts/axiom_audit.lean (the #print axioms lines) and the intended-set literal inside
scripts/check_census_and_axioms.py. Adding a declaration to only one of them fails the gate with
printed declaration set differs from the intended audit list.
CI coverage differs by trigger: every PR builds the Lean project and the blueprint (web and
PDF) and runs both gates above; the master deployment additionally builds the API
documentation and the Jekyll homepage before assembling and publishing the site.
The triangle inequality for cut distance originally rested on a single monolithic statement,
exists_common_extension, which was shown to be unprovable as stated. It was replaced by four
corrected coupling cores, all proved from the atomless standard-Borel measure-isomorphism theorem
developed graphon-independently in Graphon/MeasureIso.lean. Three cores live in
Graphon/CutDistance.lean; the fourth, the overlay theorem
exists_mpEquiv_cutNormDiff_lt_add, is proved in Graphon/Overlay.lean — the coupling matrix is
realized exactly by a measure-preserving bijection, with no appeal to Birkhoff.
first_sampling_lemma (Lovász Lemma 10.16 / BCLSV Theorem 4.6): for every ε and η there is a
sample size k that works for every graphon simultaneously. Proved by recombining two
independently established concentration events — the pointwise AFKK cut-guessing bound
(Graphon/SamplingPointwise.lean, using McDiarmid-at-MGF and soft-max infrastructure) with the
finite rounding certificate (Graphon/SamplingRounding.lean).
matrix_quotient_of_weightedHomSum_eq (Lovász Theorem 5.30, the k ≥ 2 positive-weight case), via
the twin-free bijection twinfree_bijection_of_weightedHomSum_eq and the cross-matrix
super-surjective transfer in Graphon/CrossSuper.lean.
Several statements in MatrixDetermination.lean, Lovasz.lean, and Spectral.lean had been
retained as sorry-carrying stubs after being discovered to be false. All were deleted, along
with a dead 66-declaration private subtree, and their refutations were kept as prose notes at the
original sites — including the C₅ ⊔ C₆ and identity-matrix automorphism counterexamples. The
census gate was tightened to strictly zero at the same time.
Graphon/Spectral.lean remains in the tree as documentation of the refuted closed-walk
conjectures (issue #77) and is deliberately outside the root import tree.