For every location L, evaluated nightly at 21:00 and reported to #n8n-updates:

ledger_balance(L, STOCK)
  = SUM(carton_lines.qty_current where carton at L, seal in (sealed, opened))
  + SUM(picking_area_stock.qty where location = L)
Four clauses make it hold, and each one corresponds to a real defect in the system i3 is replacing:

1. An opened carton contributes only its remaining line quantity, because opening it debited those lines. In ops2 today, opening a carton credits the picking area and leaves the carton at full quantity, so every one of the 38 opened cartons here would be counted twice.

2. A voided or archived carton contributes zero.

3. A sub-carton contributes its own quantity and its parent contributes nothing, so the parent rollup never double counts.

4. Stock held under a non-STOCK type, the 72 units in QC_HOLD and the 120 in RTS_STAGING, is excluded from this identity and checked by its own per-type identity.

Today: Δ0 for 6 consecutive days. GATE 5 needs 7 at under 0.5%.

A zone says where in the building. A stock type says what condition and whose custody. They are different axes and conflating them is how i2 ended up with location tiles that did not add up.

Moving a carton from 319_A3 to 319_A1 changes the zone and nothing else: no ledger row is written, only a carton_events row, because the location and the stock type are unchanged. Moving it from RECEIVING to QC_HOLD changes the stock type from RECEIVED_NOT_INVOICED to QUARANTINE, so it does write a ledger pair.

That single rule removes about 60% of the ledger rows the ops2 bridge writes today, including the self-cancelling split_out and split_in pairs it emits for splits that never leave the building.

The same rule at a store is what makes the display floor work: the STOCKROOM to DISPLAY move is a stock-type change (STOCK to DISPLAY_GOOD) at an unchanged location, which is exactly RFID scenario S33.

And a location is not a stock type either. The supplier pipeline sitting on this page as IN_PRODUCTION and GIT_INBOUND is stock types at HQ_319, not two extra locations. HQ_319 is the destination named on every open PO line, so HQ_319 is the site that chases the milestone and the DHL shipment, so HQ_319 holds the balance. i2 made them locations and the v2 mockup showed IN_PRODUCTION as its own row with 47 SKUs and AED 890K, which makes the same unit countable twice: once as a location balance and once as committed supply.