Current State ID: 5
Current State Description: The hand is empty. Block 'c' is on the table and clear. Block 'b' is on the table and clear. Block 'a' is on the table. Block 'd' is on top of block 'a' and is clear. The hand is not holding any block.

Child State ID: 6
Action Taken: unstack(d, a)
State Description: The hand is holding block 'd'. Block 'a' is clear and on the table. Block 'b' is clear and on the table. Block 'c' is clear and on the table. The hand is not empty as it is holding block 'd'.

