Parent State ID: 35
State Depth: 10
Action Taken: stack(a, b)
Action Reasoning: To achieve the goal state, we need to place block 'a' on block 'b'. Since the hand is currently holding block 'a' and block 'b' is clear, the best action is to stack 'a' on 'b'.
State Description: Block 'a' is on top of block 'b'. Block 'b' is on the table and supporting block 'a'. Blocks 'c' and 'd' are on the table and clear. The hand is empty. The diagram would show block 'a' on block 'b', with block 'b' marked as supporting and the hand empty.
Action Path: ['unstack(d, a)', 'put-down(d)', 'unstack(a, c)', 'put-down(a)', 'pick-up(d)', 'put-down(d)', 'unstack(c, b)', 'put-down(c)', 'pick-up(a)', 'stack(a, b)']
