Consider the "robot trap" in Figure 2.11.

Explain why it is so tricky for a robot to get to location g . You must explain what the current robot does as well as why it is difficult to make a more so- phisticated robot (e.g., one that follows the wall using the "right-hand rule": the robot turns left when it hits an obstacle and keeps following a wall, with the wall always on its right) to work.

An intuition of how to escape such a trap is that, when the robot hits a wall, it follows the wall until the number of right turns equals the number of left turns. Show how this can be implemented, explaining the belief state, the belief-state transition function, and the command function.