[fox46]

I think we are on different wavelenths on this one-

They did indeed only have one robot, but they brought an entire robot's worth of replacement parts assembled in one cohesive machine. When the mechanical mechanism on their machine broke, they removed the mechanical mechanism from the robot (which was the portion which excluded the control system) and installed an identical replacement part in the form of the entire mechanical mechanism to their control system. Basically, there was no definition of a replacement part- this could be a single piece, or an entire mechanism- in their case, they called the entire mechanical system a mechanism and brought an identical replacement part.