Readout acceptance follows positive interval overlap, including endpoint rejection. 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 first signal overlaps by four seconds
Signal interval 6 to 10 overlaps the window 4 to 11 by 4 seconds.
Δt=min(10,11)−max(6,4)=4
A narrow positive overlap still accepts
A later signal from 10 to 14 overlaps the same window by only 1 second, but the overlap is positive.
Δt=min(14,11)−max(10,4)=1
Touching the endpoint gives zero accepted overlap
A signal starting at 11 only touches the window endpoint at 11. Its overlap is 0, so it is rejected.