The chosen capture edge must be cited by downstream checks. 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 selected edge is a source value
The capture source is edge 1 at 8 seconds.
tedge=8s
Different selected edges expose different source times
The period stays fixed; only the selected edge index changes.
n123tn8s16s24ssourceedgeedgeedge
Later timing checks cite this same edge
A later setup or capture check cannot silently move edge 1 to another time.