anchor.diff:  start_profiling(Rootset, Pattern) ->
       start_profiling(Rootset, Pattern, ?default_options).
   start_profiling(Rootset, Pattern, Options) ->
  -    start(),
  +    ok = start_internal(),
       gen_server:call(?MODULE, {profile_start, Rootset, Pattern, undefined, Options}, infinity).
   
   stop_profiling() ->
  
positive.code: 
  divide(_,0) -> 0.0;
  divide(T,N) -> T/N.
  
negative.code: start() -> gen_server:start({local, ?MODULE}, ?MODULE, [], []).
  stop()  -> gen_server:call(?MODULE, stop, infinity).
  
  analyze() ->
      analyze(procs).
  
  