Artificial Intelligence Wiki

Let's assume we wanna write a plan to achieve a new goal, e.g. to flip a pancake. Best practice is to put this plan into one of the source-files of a plan library, e.g. cram_plan_library:

(def-goal (achieve (flip-pancake ...))
  (with-designators ((action-desig 
                       (action `((to flip))))
                     ...)
    ...
    (perform action)))

If you want other packages to also use this plan, export the goal-symbol in the package.lisp of the your plan library. Make sure to also export all designator properties used in your plan:

(desig-props:def-desig-package cram-plan-library
 ...
 (:export #:...
          #:flip-pancake
          ...)
 (:desig-properties #:to #:flip ...))

Now comes the catch: You also need to export the goal-symbol from the package cram_plan_knowledge. cram_plan_knowledge provides the functionality (holds …) which checks whether a goal has already been achieved. Thus, it needs to also needs to know about the correct symbol of :flip-pancake. Unfortunately, our plan library depends on