let compute_knowledge_given_to_intruder role_found session_id =
  let knowledge_list =
    List.map
      (fun x ->
        let if_value_term = get_if_value_type session_id x in
        match if_value_term with
(*          If_lst(l) ->
            assign_set_value l*)

          If_set(l) ->
            assign_set_value l
        | _ -> 
            if_value_term)
      (role_found#get_knowledge)
  in
  i_knowledge := concatenate_with_no_copy knowledge_list !i_knowledge