Current State ID: 13
Current State Description: Block A is being held by the hand and is no longer clear or on the table. Block B remains on block D and is clear. Block C is clear and on the table. Block D is not clear on the table. The hand is holding block A.

Child State ID: 21
Action Taken: stack(block_a, block_b)
State Description: Block A is now on block B and is clear. Block B is on block D and is not clear. Block C is on the table and is clear. Block D is on the table and is not clear. The hand is empty.

Child State ID: 22
Action Taken: put-down(block_a)
State Description: Block A is on the table and is clear. Block B remains on block D and is clear. Block C is clear and on the table. Block D is not clear and is on the table. The hand is empty.

