Parent State ID: 9
State Depth: 7
Action Taken: stack(a, c)
Action Reasoning: To move closer to the goal state, we need to stack block 'a' on block 'c'. First, the action will be to stack block 'c' on the table under block 'a'.
State Description: The hand is empty. Block 'c' is supporting block 'a' and is on the table. Block 'b' is clear and on the table. Block 'd' is on block 'a' and is clear. Block 'a' is clear and on block 'c'.
Action Path: ['unstack(b, c)', 'put-down(b)', 'unstack(c, d)', 'put-down(c)', 'unstack(d, a)', 'stack(d, a)', '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.
