Instantiated action has wrong effects

[o-fir]

For the action _(do_decontaminate env1 c1)_ of type

(:action do_decontaminate
        :parameters (?env - environment ?c - contamination)
        :precondition (and 
            (contaminated ?env ?c)  
        )
        :effect (and
            (not(contaminated ?env ?c))
        )
    )

the positive effects include (contaminated env1 c1)

Code to display effects of all actions:

 for (int i = 0; i < problem.getTasks().size(); i++) {
                Task t = problem.getTasks().get(i);
                if (t.isPrimtive()) {
                    Action ac = problem.getActions().get(i);
                    BitVector pos = ac.getUnconditionalEffect().getPositiveFluents();
                    BitVector neg = ac.getUnconditionalEffect().getNegativeFluents();
                    System.out.println("ACTION: " + PrintFunctions.taskToString(i, problem));

                    for (int g = pos.nextSetBit(0); g >= 0; g = pos.nextSetBit(g + 1)) {
                        System.out.println("+++ " + PrintFunctions.predicateToString(g, problem));
                    }
                    for (int g = neg.nextSetBit(0); g >= 0; g = neg.nextSetBit(g + 1)) {
                        System.out.println("--- " + PrintFunctions.predicateToString(g, problem));
                    }
                }
            }

    public static String predicateToString(int index, Problem problem) {
        Fluent f = problem.getFluents().get(index);
        String tmp = "";
        tmp += problem.getPredicateSymbols().get(f.getSymbol()) + "(";

        for (Integer i : f.getArguments()) {
            tmp += problem.getConstantSymbols().get(i) + ", ";
        }
        tmp += ")";
        return tmp;
    }

DOMAIN:

; problem is performing experiments
; experiments are performed in the lab by 2 scientists, after which lab equipment must be rearranged by 1 scientist
; labs are accessed via ports
; a new person can't enter a lab, if there is already someone inside.
; only one person can enter via port

(define (domain quarantine)
    (:requirements :hierarchy :negative-preconditions :equality :typing :method-preconditions)

    (:types
        contamination
        subject
        environment
        experiment
        decontamination-procedure
    )

    (:predicates
        (assigned ?e - experiment ?env - environment)
        (contaminated ?e - environment ?c - contamination)
        (carrier ?s - subject ?c - contamination)
        (decontamination-type ?d - decontamination-procedure ?c - contamination)
        (experiment-type ?e - experiment ?c - contamination)
    )

    (:task perform_experiment
        :parameters (?e - experiment)
    )

    (:task contaminate
        :parameters (?env - environment ?c - contamination)
    )

    (:task decontaminate
        :parameters (?env - environment ?c - contamination)
    )

    (:method m0_perform_experiment
        :parameters (?e - experiment ?c - contamination ?env - environment)
        :task (perform_experiment ?e)
        :precondition (and
            (experiment-type ?e ?c)
        )
        :ordered-subtasks (and
            (contaminate ?env ?c)
            (do_experiment ?e ?env ?c)
            (decontaminate ?env ?c)
        )
    )

    (:method m0_contaminate
        :parameters (?env - environment ?c - contamination)
        :task (contaminate ?env ?c)
        :precondition (and
            (not(contaminated ?env ?c))
        )
        :ordered-subtasks (and
            (do_contaminate ?env ?c)
        )
    )
    (:method m1_contaminate
        :parameters (?env - environment ?c - contamination)
        :task (contaminate ?env ?c)
        :precondition (and
            (contaminated ?env ?c)
        )
        :ordered-subtasks (and
            (nop)
        )
    )
    (:method m0_decontaminate
        :parameters (?env - environment ?c - contamination ?d - decontamination-procedure)
        :task (decontaminate ?env ?c)
        :precondition (and
            (contaminated ?env ?c)
            (decontamination-type ?d ?c)
        )
        :ordered-subtasks (and
            (do_clear_environment ?env)
            (do_initiate_decontamination ?env ?d)
            (do_decontaminate ?env ?c)
        )
    )
    (:method m1_decontaminate
        :parameters (?env - environment ?c - contamination)
        :task (decontaminate ?env ?c)
        :precondition (and
            (not(contaminated ?env ?c))
        )
        :ordered-subtasks (and
            (nop)
        )
    )

    (:action do_experiment
        :parameters (?e - experiment ?env - environment ?c - contamination)
        :precondition (and 
            (contaminated ?env ?c)
            (experiment-type ?e ?c)
        )
        :effect (and
        )
    )

    (:action do_contaminate
        :parameters (?env - environment ?c - contamination)
        :precondition (and )
        :effect (and
            (contaminated ?env ?c)
        )
    )

    (:action do_clear_environment
        :parameters (?env - environment)
        :precondition (and )
        :effect (and
        )
    )

    (:action do_initiate_decontamination
        :parameters (?env - environment ?d - decontamination-procedure)
        :precondition (and )
        :effect (and
        )
    )

    (:action do_decontaminate
        :parameters (?env - environment ?c - contamination)
        :precondition (and 
            (contaminated ?env ?c)  
        )
        :effect (and
            (not(contaminated ?env ?c))
        )
    )

    (:action nop
    :parameters ()
    :precondition ()
    :effect ())
)

PROBLEM:

; num_oven: 2
; num_brick: 4
; num_temp: 2

(define
   (problem pfile0)
   (:domain quarantine)
   (:objects
      c1 - contamination
      e1 e2 e3 - experiment
      env1 - environment
      d1 - decontamination-procedure
   )

   (:htn
      :parameters ()
      :subtasks (and
         (task0 (perform_experiment e1))
         (task1 (perform_experiment e2))
         (task2 (perform_experiment e3))
      )
   )

   (:init
      (experiment-type e1 c1)
      (experiment-type e2 c1)
      (experiment-type e3 c1)
      (decontamination-type d1 c1)
   )
)