The GRT Planner

The main idea that arise during the forward search phase and of the planner is to compute offline, in the preprocessing the goals. This approach succeeds in the notion of related facts in the goal-regression avoiding computing estimates for invalid facts process. These are facts that have been achieved in the preprocessing phase. However, it introduces either by the same or subsequent actions, without some problems in situations where the the last actions deleting the facts achieved goal state is not completely described because first. The cost of achieving simultaneously a set an action to regress the goals might not exist. of unrelated facts is considered equal to the To cope with this situation, at the beginning sum of their individual costs, whereas the cost of the preprocessing phase, We know from our experience that if move actions were Table 1.