Move In(a) In(B) noo In(B) In(B) Closed Closed Closed Opened Polished Note that this plan graph has two action layers, one to open the door, and the second to act based on the open door (also note that the plan graph includes move operations, but are not indicated here for simplicity). The relaxed plan consists of Open, followed by Polish, with a heuristic cost of 2. This does not represent an improvement over Node 3, ence we try expanding Node 3 using action Polish, producing Node 5 Node 1 In(a) Estimate 3 Closed Open Node 2 In(a) Estimate 3 Opened Move(A B Polish Node 3 In(B) Estimate 2 Opened Polish Node 4 n(B)Estimate 2 In(B)Estimate? Polished The relaxed plan graph for Node 5 isPolish noop noop noop Close Move In(A) In(B) Closed Opened Polished In(B) Closed Opened In(B) Closed noop Open noop Note that this plan graph has two action layers, one to open the door, and the second to act based on the open door (also note that the plan graph includes move operations, but are not indicated here for simplicity). The relaxed plan consists of Open, followed by Polish, with a heuristic cost of 2. This does not represent an improvement over Node 3, hence we try expanding Node 3 using action Polish, producing Node 5: Node 1 In(A) Estimate 3 Closed Open The relaxed plan graph for Node 5 is: Node 2 In(A) Estimate 3 Opened Move(A,B) Polish Node 3 In(B) Estimate 2 Opened Estimate 2 Close In(B) Closed Node 4 In(B) Estimate ? Opened Polished Polish Node 5