(unstack purple green robot)
(put-down purple robot)
(unstack green yellow robot)
(put-down green robot)
(pick-up purple robot)
(stack purple green robot)
(unstack yellow blue robot)
(put-down yellow robot)
(unstack blue orange robot)
(put-down blue robot)
(unstack orange red robot)
(put-down orange robot)
(pick-up red robot)
(stack red blue robot)
(pick-up yellow robot)
(stack yellow orange robot)