A latch-window scan makes the half-open capture interval explicit, so an arrival at the left edge is accepted while one at the right edge is not. The capture decisions are exact only for the declared window endpoints, input arrival times, ideal digital levels, and deterministic latch model; real latches include aperture uncertainty, setup/hold variation, metastability risk, clock skew, threshold drift, load effects, and timing/voltage measurement uncertainty.
The half-open latch window captures the left endpoint and blocks the right endpoint. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Arrival at the left endpoint is inside the latch window
The latch window is [4, 7) seconds. Arrival at 4 seconds makes the gate capture and output 1.
4≤4<7,Q=1
Interior arrival also copies the input
The latch window is [4, 7) seconds. Arrival at 6 seconds makes the gate capture and output 1.
4≤6<7,Q=1
Arrival at the right endpoint is blocked
The latch window is [4, 7) seconds. Arrival at 7 seconds makes the gate block and output 0.