A receive window is valid only while the required control window covers it. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
A receive window needs coverage
The required gradient window starts at 2 s and ends at 8 s.
required=[2s,8s]
Receive sits inside the required window
The receive window also runs from 2 s to 8 s, so the alignment closes. This does not model real gradient slew.