Control, waiting, and readout stages spend a finite coherence window, so their durations must be added before the acceptance test. The fit is exact only for the stated stage times and window limit; real systems include timing jitter, pulse-shape tails, decoherence, detector latency, and calibration drift.
A control sequence must fit inside a declared finite 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
Stage times add before the window test
Prepare takes 2 seconds, control takes 3 seconds, and readout takes 4 seconds.
2+3+4=9
The elapsed time fits the coherence window
The elapsed time is 9 seconds, which fits inside the 10 second window.