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