A matched pulse readies the target state in this finite model because its value equals the target gap while missing the neighbor gap. The true/false response is exact only for the stated gaps, pulse value, and ideal selectivity; real hardware has finite bandwidth, off-resonant drive, leakage, relaxation, and readout uncertainty.
Selective control means the target comparison is true while the neighbor comparison is false. 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 target transition matches
The pulse 6 equals the target gap 6, so the target response is checked true.
6=6
The neighbor transition stays off
The same pulse 6 does not equal the neighbor gap 4, so the neighbor response is checked false.