anchor.diff:  			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) ->
  +			Auras ++ [{call, ?MODULE, decode_res, [Res]}];
  +		true ->
  +			rpgb:splice(Auras, Next, 0, [{call, ?MODULE, decode_res, [Res]}])
  +	end,
  +	State#state{auras = Auras2};
   next_state(#state{zones = Zones} = State, Res, {call, _, delete_zone, [Nth, _]}) ->
   	State#state{zones = rpgb:snip(Nth, Zones)};
   next_state(State, _Res, _Call) ->
  
positive.code: 	oneof([undefined, null, g_existant(Zones)]);
  g_next(aura, #state{auras = []}) ->
  	null;
  g_next(arua, #state{auras = Auras}) ->
  	oneof([undefined, null, g_existant(Auras)]).
  
  g_existant([]) ->
  
negative.code: 
  precondition(S, {call, _, create_zone, _}) ->
  	true;
  precondition(S, {call, _, create_aura, _}) ->
  	true;
  precondition(S, {call, _, delete_zone, [_, #state{zones = Z}]}) when length(Z) >= 1 ->
  	true;
  precondition(_,_) ->
  