Processus
Messages

-module (msgs).
-export ([start/0, counter/1, get/1]).

start () ->
    spawn (?MODULE, counter, [1]).

counter (N) ->
    receive
        Sender -> Sender ! N
    end,            
    counter (N+1).

get (PID) ->
    PID ! self (),
    receive
        Answer -> Answer
    end.