Parent State ID: 3
State Depth: 3
Action Taken: pick-up(a)
Action Reasoning: To move towards the goal state, we need to stack block 'a' on block 'c'. First, we must pick up block 'a' from the table since the hand is empty and block 'a' is clear.
State Description: The hand is now holding block 'a'. Block 'a' is no longer on the table or clear. Block 'd' remains on top of block 'a' and is clear. Block 'b' is on the table and clear. Block 'c' is on the table and clear.
Action Path: ['unstack(c, d)', 'put-down(c)', 'pick-up(a)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: Block 'a' is not clear, violating the precondition for pick-up(a).
