Proof of `Valtr's four-layer lemma`
groundedproofs/Lax570090Proofs/ValtrFourLayer.lean · lax-570090
What this proof establishes
no assumptions
Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.
Description
Valtr's four-layer implication with the deliberately unoptimized outer threshold sixteen. The convex endpoint case is proved by edge caps and backward projective propagation, not assumed.