A Planner Called R

STRIPS (as given in Nilsson [1998, pp. I now illustrate the planning algorithm with an example from the blocks world. In the version given at the Fifth International Conference on Artificial Intelligence Planning and Scheduling (AIPS'00) competition, there are four actions, given below in Although the planner returns a reasonable plan in the previous example, this might not be the case in general. For example, given the same initial situation description and the goal on(a, b), on(b, c), it returns the plan [unstack(c, b), putdown (c), unstack(b, a), putdown(b), pickup(a), stack(a, b), unstack(a, b), putdown(a), pickup(b), stack(b, c), pickup(a), stack(a,b)] which is obviously not a good one. For the AIPS'00 competition, our team implemented the following strategy for postprocessing: Remove all immediate cycles.