Current State ID: 41
Current 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, block 'b' is lifted from the table, and the hand is holding block 'b'.

Child State ID: 47
Action Taken: stack(b, c)
State Description: Block 'a' is on top of block 'd', block 'b' is on top of block 'c', and both blocks 'a' and 'b' are clear. The hand is empty. In the diagram, block 'b' is now stacked on block 'c', completing the goal state.

Child State ID: 48
Action Taken: stack(b, c)
State Description: Block 'a' is on top of block 'd', both are on the table. Block 'c' has block 'b' stacked on top of it, making block 'b' not clear. The hand is now empty.

