I was going to assign problem 4.13 to my AI students as a good continuation of 3.7, but I find that it requires problem 4.11. I looked at problem 4.11 and the part related with the percepts and the knowledge of the map is clear. However, in problem 3.7 navigation is based on straight line segments between vertices of the polygons. In problem 4.11, it is not clear what happens after the agent stops where the path intersects an obstacle (second bullet). Should it compute another path to try to get to the goal state, or start anew from a random location. I am assuming it is using an online search algorithm.
Thanks for your collaboration,