Three Way Invoice Match

Each paired line takes the first verdict that applies in a fixed order: quantity over received, receipt missing (a two-way match, reported as a flag rather than a failure), quantity over ordered, or unit price outside the declared basis-point tolerance, where a variance exactly at the tolerance passes. Totals are recomputed from the line sum, half-up tax at one declared rate, and the total from those two. Prior invoices from the same vendor are screened on the normalized invoice number, same total inside the declared day window, or the same PO. Fractional quantities and sub-minor-unit prices are refused with a named reason, never rounded; one currency per invoice; no tax-jurisdiction logic; day differences come from integer days-from-civil arithmetic with no clock. No formal correctness proof exists for this node yet (compute_proof_ready: deferred); see the proof-status note below the results.