Recomputes per-day interest accrual over a day-count convention and compounding basis you declare, then diffs the recomputed cumulative total against your core's own posted accrual or interest-paid ledger entry. Returns MATCHES, DIVERGES with the exact divergence, or INDETERMINATE when there is nothing to diff against. An independent recompute-and-receipt over your own declared inputs, not an audit of your core, and not a claim about which convention it should use.