(define (domain waiting)
    (:requirements :adl )

    (:types
        waiter
        location
        plate
        customer
        ;; Fill in additional types here
    )

    (:constants
        ;; You should not need to add any additional constants
        Agent - waiter
        BUFF - location
    )

    (:predicates
        ;; Example:
        ;; (Contains ?x - object ?c - container)
        (HoldingPlate ?x - waiter ?p - plate)
        (Adjacent ?a - location ?b - location)
        (HasFood ?p - plate)
        (Served ?c - customer)
        (At ?o - object ?l - location)
    )

    ;;;; Action Template - Delete and fill in own actions ;;;;

    ;(:action dummy-action
    ;    :parameters (?obj - object)
    ;    :precondition (and
    ;        (dummy-pred-1 ?obj)
    ;        (dummy-pred-2 ?obj)
    ;    )
    ;    :effect (and
    ;        (not (dummy-pred-1 ?obj))
    ;        (dummy-pred-3 ?obj)
    ;    )
    ;)

    (:action Pick-Up-Plate
        :parameters (?x - waiter ?p - plate ?l - location)
        :precondition (and
            (not (HoldingPlate ?x ?p))
            (At ?x ?l)
            (At ?p ?l)
        )
        :effect (and
            (HoldingPlate ?x ?p)
            (not(At ?p ?l))
        )
    )

    (:action Hand-Over-Plate
        :parameters (?x - waiter ?p - plate ?l - location ?c - customer)
        :precondition (and
            (HoldingPlate ?x ?p)
            (At ?x ?l)
            (At ?c ?l)
            (At ?p ?l)
        )
        :effect (and
            (not(HoldingPlate ?x ?p))
            (Served ?c)
        )
    )

    (:action Fill
        :parameters (?x - waiter ?p - plate)
        :precondition (and
            (HoldingPlate ?x ?p)
            (not(HasFood ?p))
            (At ?x BUFF)
        )
        :effect (and
            (HasFood ?p)
        )
    )

    (:action Move
        :parameters (?x - waiter ?from - location ?to - location)
        :precondition (and
            (At ?x ?from)
            (not (= ?from ?to))
            (Adjacent ?from ?to)
        )
        :effect (and
            (not (At ?x ?from))
            (At ?x ?to)
        )
    )

)