Addressing one ion updates the shared packet source. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
The addressed ion uses a checked drive
The drive starts from packet 2 and ends at packet 1.
2→1
A red sideband on ion A lowers the shared packet
Ion A cites the same shared packet ledger, ending at packet 1.