Classifies a settlement position under one of three settlement models: an optimistic challenge window, a validity proof, or single-slot BFT consensus. Each model has its own tier ladder and the ladders are never merged, because a posted batch on an optimistic rollup and a committed batch on a validity rollup are not the same claim. If a counterparty asserts a higher tier than the evidence supports, the claim is flagged as overstated.
ART-321 BoLD Challenge-Window Finality Classifier classifies an optimistic challenge window on one named deployment. ART-290 Linea L2 Finality Window Check covers a validity rollup with a three-state model. Both remain live and continue to resolve, so receipts they produced stay verifiable.