Teaching Case — More Reports Assessed Than Records Screened

Records only ever leave a review funnel, so every count must be no larger than the one before it. Here 640 reports are assessed for eligibility out of the 380 that were sought — 260 reports appear from nowhere, which no sequence of events could produce. It is decidable with no remainder at all, so it is caught even where the ledger cannot run, and it reads as a perfectly ordinary diagram: the boxes are the same size whatever numbers are in them.