(define (domain logistics-domain)
 (:requirements :typing
                :equality
                :disjunctive-preconditions
                :probabilistic-effects
                :existential-preconditions
                :conditional-effects
                :rewards)
 (:types city box)
 (:constants newyork - city
             chicago - city
             losangeles - city
             detroit - city)
 (:predicates (box-at-city ?b - box ?c - city)
              (destination ?b - box ?dst - city)
 )

 (:action drive-box
  :parameters (?b - box ?src - city ?dst - city) ;;box, source, destination
  :precondition (and
                 (not (destination ?b ?src))
                 (box-at-city ?b ?src) ;;make sure the box is at src
                 (or ;;now make sure the box can go to dst from src
                  (and (= ?src newyork) ;;newyork
                       (or (= ?dst chicago) ;;can go to chicago
                       )
                  )
                  (and (= ?src chicago) ;;chicago
                       (or (= ?dst newyork) ;;can go to newyork
                       )
                  )
                 )
                )

  :effect (and
           (not (box-at-city ?b ?src)) ;;take the box out of the city
           (and

            (when
             (= ?src newyork) ;;for newyork
             (probabilistic
              0.2 (probabilistic ;;box gets lost, send to random adjacent city
                   0.3 (and
                        (decrease (reward) 10) ;;the cost to go to chicago
                        (box-at-city ?b chicago)
                        (when (destination ?b chicago) (increase (reward) 50))
                       )
                   0.7 (box-at-city ?b newyork)
                  )
              0.8 (and ;;most of the time you get where you want to
                   (when (= ?dst chicago) (decrease (reward) 10))
                   (when (destination ?b ?dst) (increase (reward) 50))
                   (box-at-city ?b ?dst) ;;put the box at dst
                  )
             )
            )

            (when
             (= ?src chicago) ;;for chicago
             (probabilistic
              0.2 (probabilistic ;;box gets lost, send to random adjacent city
                   0.3 (and
                        (decrease (reward) 10) ;;the cost to go to newyork
                        (box-at-city ?b newyork)
                        (when (destination ?b newyork)
                              (increase (reward) 50)
                        )
                       )
                   0.7 (box-at-city ?b chicago)
                  )
              0.8 (and ;;most of the time you get where you want to
                   (when (= ?dst newyork)
                         (decrease (reward) 10)) ;;cost for chicago
                   (box-at-city ?b ?dst) ;;put the box at dst
                   (when (destination ?b ?dst)
                         (increase (reward) 50)
                   )
                  )
             )
            )

           )
;;           (when (exists (?city - city)
;;                         (and (box-at-city ?b ?city)
;;                              (destination ?b ?city)
;;                         )
;;                 )
;;                 (increase (reward) 50)
;;           )
          )
 )
)

(define
 (problem logistics-problem)
  (:domain logistics-domain)
  (:objects mybox - box)
  (:init (box-at-city mybox newyork)
         (destination mybox chicago)
  )
  (:metric maximize (reward))

)