Undeclared variables in PDDL

Question

I am trying to generate an AI plan using PDDL. here is my problem and domain files

problem.pddl

;Header and description


(define (problem lung-cancer-problem)

    (:domain lung-cancer)
    (:objects
        patient1 - patient
        model1 model2 model3 - model)
    (:init
        (not (model-trained model1))
        (not (model-trained model2))
        (not (model-trained model3)))
    (:goal
        (and (model-diagnoses model1 patient1)
             (model-diagnoses model2 patient1)
             (model-diagnoses model3 patient1)
             (or (has-lung-cancer patient1)
 
                (not (has-lung-cancer patient1))))))


domain.pddl

;Header and description
(define (domain lung-cancer)
;remove requirements that are not needed
(:requirements :strips  :typing :conditional-effects :negative-preconditions :duration-inequalities :equality)

(:types patient model - object)

(:predicates    (has-lung-cancer ?p - patient)
                (model-trained ?m - model)
                (model-diagnoses ?m - model ?p - patient)
)

    (:action train-model
        :parameters (?m-model)
        :precondition (not(model-trained ?m))
        :effect (and (model-trained ?m))
    )
    (:action diagnose-patient
        :parameters (?p-patient ?m-model)
        :precondition (and(model-trained ?m))
        :effect (and (model-diagnoses ?m ?p)
            (or (has-lung-cancer ?p)
                (not (has-lung-cancer ?p))))
    )

)

I am getting error undeclared variable ?m and ?P in the domain file (or (has-lung-cancer ?p) (not (has-lung-cancer ?p)))) Syntax error in the action declaration

How do I solve these?

I generated the codes using ChatGPT

Answer 1

You need spaces around the - in your :parameters block. More importantly, you probably should write the PDDL yourself, since ChatGPT isn't (yet) capable of producing decent PDDL (obviously).