Where is the plan in planning.domain solver?

Question

(define (domain dungeon_hero)
(:requirements :strips :adl :typing :negative-preconditions) ;; There is use of negative-preconditions in the domain
(:types hero room sword monster trap clear) ;; Various types used

(:predicates    (connected ?r1 -room ?r2 -room)     ;; defines that two rooms are connected and will be defined twice for bi-directional connection
        (at-hero ?h -hero ?r -room)                 ;; defines what is there in which room i.e.hero,trap,monster or room is clear       
            (monster-in ?m -monster ?r1 -room)      ;; defines a monster in a room
        (trap-in ?t -trap ?r -room)                 ;; defines a trap in a room
        (sword-in ?s -sword ?r -room)               ;; defines a sword in a room
            (clear-room ?r -room)                   ;; defined a room is clear
            (handempty ?h -hero )                   ;; TRUE if the Hero's hand is empty
            (haveSword ?s -sword )                  ;; if the hero is holding the sword
        (alive ?h -hero)                            ;; If the hero is alive
        (exist ?r -room)                            ;; If the room is not destroyed i.e. after the visit
)

(:action visit2sword
     :parameters (?h -hero ?from -room ?to -room ?s -sword ?t -trap ?m -monster)
     :precondition (and (at-hero ?h ?from)(alive ?h) (exist ?to)(sword-in ?s ?to)(connected ?from ?to) )
     :effect
        (and (not (at-hero ?h ?from))
       (not(exist ?from))   
       (at-hero ?h ?to)
       (not(monster-in ?m ?to))     
        (not(trap-in ?t  ?to))              


    )       
)


(:action pick-up-sword
     :parameters (?h -hero ?r -room ?s -sword )
     :precondition (and (at-hero ?h ?r)(alive ?h) (sword-in ?s ?r) (handempty ?h))
     :effect
        (and (not (handempty ?h))
       (haveSword ?s)
    (not(sword-in ?s ?r))
    )       
)



(:action visit2monster
     :parameters (?h -hero ?from -room ?to -room ?s -sword ?m -monster ?t -trap)
     :precondition (and (at-hero ?h ?from)(alive ?h)(not(handempty ?h))(exist ?to)(haveSword ?s)(monster-in ?m ?to) (connected ?from ?to) )
     :effect
        (and (not (at-hero ?h ?from))
       (not(exist ?from))   
       (at-hero ?h ?to)

        (not(trap-in ?t  ?to))                  
        (not(sword-in ?s ?to))
    )       
)


(:action visit2trap
     :parameters (?h -hero ?from -room ?to -room ?s -sword ?t -trap)
     :precondition (and (at-hero ?h ?from)(alive ?h)(not(haveSword ?s))(handempty ?h)(trap-in ?t ?to) (exist ?to)(connected ?from ?to) )
     :effect
        (and (not (at-hero ?h ?from))
       (not(exist ?from))   
       (at-hero ?h ?to)

    )       
)
(:action visit2clear
     :parameters (?h -hero ?from -room ?to -room ?s -sword ?t -trap ?m -monster)
     :precondition (and (at-hero ?h ?from)(alive ?h)(clear-room ?to)(exist ?to)(connected ?from ?to) )
     :effect
        (and (not (at-hero ?h ?from))
       (not(exist ?from))   
       (at-hero ?h ?to)
        (not(monster-in ?m ?to))        
        (not(trap-in ?t  ?to))                  
    ;;  (not(sword-in ?s ?to))

    )       
)


(:action destroy-sword
     :parameters (?h -hero ?t -trap  ?s -sword ?m -monster ?r -room   )
     :precondition 
     ((at-hero ?h ?r)(alive ?h) (haveSword ?s)(not(monster-in ?m ?r)) (not(trap-in ?t ?r)
    ;;(and(at-hero ?h ?r)(alive ?h) (haveSword ?s)(not(monster-in ?m ?r)) (not(trap-in ?t ?r)) 
    )
     :effect
        (and (handempty ?h)
       (not(haveSword ?s))

    )
)

(:action disarm ;; Disarm the trap to
     :parameters (?h -hero ?t -trap ?r -room  )
     :precondition (and(at-hero ?h ?r)(alive ?h)(handempty ?h)(trap-in ?t ?r)  )
     :effect
     (and (not (trap-in ?t ?r))
     )

)

(:action getkilled ;; Disarm the trap to
     :parameters (?h -hero ?m -monster ?s -sword ?r -room  )
     :precondition (and(at-hero ?h ?r)(alive ?h)(handempty ?h)(monster-in ?m ?r)(not(haveSword ?s))) ;;
     :effect
     (and (not (alive ?h))
     )         
)  
)

(define (problem T2PROBLEM-1)
(:domain dungeon_hero)
(:objects d0-1 d1-1 d1-2 d2-1 d2-2 d3-1 d3-2 d4-1 - room
sword1 - sword 
mon1 mon2 - monster
clear1 clear2 - clear 
trap1 - trap
h1 - hero
;;h1 -hand
)

(:INIT 

    ;; Initial status of the hero h1
    (at-hero h1 d0-1)
    (alive h1)
    (handempty h1)


    ;; content of each room

    (sword-in sword1 d1-1)
    (monster-in mon1 d1-2)
    (monster-in mon2 d2-1)
    (trap-in trap1 d1-1)
    (clear-room d2-2)
    (clear-room d3-2)
    (clear-room d4-1)

;; All rooms exist at the initial state and hence exist should be TRUE
(exist d0-1) (exist d1-1) (exist d1-2) (exist d2-1) (exist d2-2) 
(exist d3-1) (exist d3-2) (exist d4-1)

;; Rooms are connected in both direction being undirected graph
(connected d0-1 d1-1)(connected d1-1 d0-1)
(connected d0-1 d1-2)(connected d1-2 d0-1)
(connected d1-1 d1-2)(connected d1-2 d1-1)
(connected d1-1 d2-1)(connected d2-1 d1-1)
(connected d1-2 d2-2)(connected d2-2 d1-2)
(connected d2-1 d2-2)(connected d2-2 d2-1)
(connected d2-1 d3-1)(connected d3-1 d2-1)
(connected d2-2 d3-2)(connected d3-2 d2-2)
(connected d3-1 d3-2)(connected d3-2 d3-1)
(connected d3-1 d4-1)(connected d4-1 d3-1)

)

(:goal (AND (ALIVE h1)  (AT-hero h1 d4-1)))
)

Answer 1

Your domain model is not valid PDDL.

Action "destroy-sword" has an "incorrect" precondition specification.

:precondition 
     ((at-hero ?h ?r)(alive ?h) (haveSword ?s)(not(monster-in ?m ?r)) (not(trap-in ?t ?r)
    ;;(and(at-hero ?h ?r)(alive ?h) (haveSword ?s)(not(monster-in ?m ?r)) (not(trap-in ?t ?r)) 
    )

Should this precondition be as follows?

:precondition 
     (and (at-hero ?h ?r)(alive ?h) (haveSword ?s)(not(monster-in ?m ?r)) (not(trap-in ?t ?r)
    ;;(and(at-hero ?h ?r)(alive ?h) (haveSword ?s)(not(monster-in ?m ?r)) (not(trap-in ?t ?r)) 
    ))

If you specify it as described above, the output of the planner is " ff: goal can be simplified to FALSE. No plan will solve it". So the specified planning problem has no plan.