Consider a robot with two vision sensors mounted on each side $($like the eyes of a frog$).$ The robot searches for red coke cans among stacks of white newspapers. When it sees a red can, it moves to the can, grasps the can, and then begins searching for a blue recycling bin. When it sees the bin, the robot moves to the bin and deposits the can. If it sees a white bundle, it avoids it$.$ The robot repeats the cycle ad infinitum.