Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Forward reachable path: The black horizontal lines represent nodes, and the blue shaded regions represent active edges. The red line is a forward reachable path from node 1 to 4, within [t0, tmax]. There is a path even though the cross-sectional network at t1 has no active connecting edges. The dotted path also connects node 1 to 4, but takes a longer time.
