[virtual-signal=signal-1] 1-5 is typically constructed using two loopbacks. [virtual-signal=signal-2] The two loopbacks are usually from the same branch, but they don't have to be. [virtual-signal=signal-3] If we ignore one of the splitters, [virtual-signal=signal-4] the two loopback splitters can be merged into one loopback splitter. [virtual-signal=signal-5] The belts neighboring the loopbacks are also merged, and can be split 1-3 to make a new 1-5.