Current State ID: 29
Current State Description: Block 'a' is now on top of block 'd', and both blocks 'b' and 'c' remain clear and on the table. The hand is empty. In the diagram, 'a' is stacked on 'd', and the hand is no longer holding any block.

Child State ID: 37
Action Taken: pick-up(b)
State Description: Block 'a' is on top of block 'd', block 'c' is clear and on the table, and block 'b' is held in the hand. The hand is no longer empty. In the diagram, 'b' is lifted from the table, and 'c' remains clear.

