Item 58: Composition of the reason state with the record calculus

The reason state is designed to compose with the record calculus — occurrences and their sources on one side, undertaken liabilities and their accounts on the other — and the composition is not verified. The two carry the same shape in different vocabularies: the account DAG the answerability kernel uses for liabilities is the dependency structure the reason ledger uses for occurrences, and nothing shows that a query answered in one is the query answered in the other.

Deliverable shape: a composition statement with a finite model of both sides, and the counterexample distinguishing it from a claim that the two structures are the same object. Acceptance check: both lines' existing fixtures run against the composed model, and a basis-loss event on the reason side produces exactly the record-side review the calculus specifies. Context: .../2026-08-23-reason-representation/MEMO.md, What is not established; .../2026-08-21-internal-answerability/MEMO.md §6. Consumed by: any end-to-end legitimacy round, which needs both layers at once and currently has to assume they compose.