Parent State ID: 9
State Depth: 5
Action Taken: stack(a, c)
Action Reasoning: To start building the goal stack, we should first stack block 'a' on block 'c' since both are clear and on the table.
State Description: Block a is on block c. Block c is on the table and no longer clear. Block a is clear. Block b is on the table and clear. Block d is on the table and clear. The hand is empty.
Action Path: ['unstack(c, d)', 'put-down(c)', 'unstack(d, a)', 'put-down(d)', 'stack(a, c)']

INACTIVE REASON: deactivated because diagram generation failed or invalid action chosen: The hand is not holding block 'a', violating the precondition for the stack action.
