anchor.diff:  	true;
   precondition(S, {call, _, delete_zone, [_, #state{zones = Z}]}) when length(Z) >= 1 ->
   	true;
  +precondition(S, {call, _, delete_aura, [_, _, #state{auras = A}]}) when length(A) >= 1 ->
  +	true;
   precondition(_,_) ->
   	false.
   
  
positive.code: 	true;
  
  postcondition(State, {call, _, delete_zone, _}, {ok, "204", _, _}) ->
  	true;
  
  postcondition(S, C, R) ->
  
negative.code: 			rpgb:splice(Zones, Next, 0, [{call, ?MODULE, decode_res, [Res]}])
  	end,
  	State#state{zones = Zones2};
  
  next_state(#state{auras = Auras} = State, Res, {call, _, create_aura, [_Put, _Name, Next, _Putter, _S]}) ->
  	Auras2 = if
  		is_atom(Next) ->
  