Universal server from Joe Armstrong, can I make it turn back into a universal server after?

fav1.erl

-module(fav1).
-export([test/0]).

test() ->
    Pid = spawn(fun universal_server/0),
    Pid ! {become, fun fac_server/0},
    Pid ! {self(), 50},
    receive
	Y -> Y
    end,
    Pid2 = spawn(fun universal_server/0),
    Pid2 ! {become, fun fib_server/0},
    Pid2 ! {self(), 50},
    receive
	X -> X
    end,
    {X, Y}.

universal_server() ->
    receive
	{become, F} -> F()
    end.

fac_server() ->
    receive
	{From, N} ->
	    From ! factorial(N),
	    fac_server()
    end.

factorial(0) -> 1;
factorial(N) -> N * factorial(N-1).

fib_server() ->
    receive
        {From, N} ->
            From ! fib(N),
            fib_server()
    end.

fib(0) -> 0;
fib(1) -> 1;
fib(N) -> N + fib(N-1).

%% in repl:
%% > c(fav1).
%% > fav1:test().
%% {30414093201713378043612608166064768844377641568960512000000000000, 1275}