Elapsed stage time is compared with the declared coherence window. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Elapsed stage time is compared with the coherence window
The same window is kept fixed; each row changes the declared stage durations.
m=Twindow−Telapsed
Three elapsed times bracket the window edge
The middle row exactly uses the whole window. The last row exceeds it.