Current State ID: 39
Current State Description: Block 'b' is held in the hand. Block 'c' remains clear and on the table. Block 'a' is on top of block 'd', and block 'd' is supporting block 'a'. The hand is no longer empty.

Child State ID: 46
Action Taken: stack(b, c)
State Description: Block 'b' is now on top of block 'c', and block 'c' is supporting block 'b'. The hand is empty. Block 'a' remains on top of block 'd', and block 'd' is supporting block 'a'. The diagram would show block 'b' stacked on block 'c', with both blocks on the table.

