The final ultrasound report is accepted only by cited source checks. 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 audit cites each source ledger
Depth 12 meters, reflection ratio 1 over 2, resolution limit 4 meters, and shift 4 hertz are all source-bound.
12m,R=21,Δd=4m,Δf=4Hz
The accepted bit requires every source gate
The final report is accepted only because the range gate is active, the resolution gate passes, and every cited value matches its source.