A transparent latch copies its input only while its enable window is open, so arrival time decides whether the stored state updates. The half-open 4 s to 7 s window is an exact timing convention for this ledger; real latches have aperture uncertainty, propagation delay, metastability risk, clock skew, voltage thresholds, and measurement tolerance.
The latch window is half-open and checked by exact arrival time. 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 transparent latch captures inside its open window
The latch is open from 4 seconds to just before 7 seconds, and the input arrives at 5 seconds.
4≤5<7
Arrivals before the right endpoint are captured
The half-open window accepts interior arrivals and blocks the endpoint row.
tD5s6s7sQ110gatecapturecaptureblock
The right endpoint is blocked by convention
An arrival exactly at 7 seconds is outside the half-open window, so the output stays 0.