anchor.diff:  
   start_test() ->
       {ok, _Pid} = start(),
  +
       ?assert(is_process_alive(whereis(?math_server))),
   
       aftereach().
   
   already_started_test() ->
       {ok, _Pid} = start(),
  -    ?assert(is_process_alive(whereis(?math_server))),
   
       Result = case catch start() of
   		 M ->
  
positive.code: 
  stop_test() ->
      {ok, _Pid} = start(),
      ?assert(is_process_alive(whereis(?math_server))),
      ServerPid = whereis(?math_server),
  
      stop(),
  
      receive after 1 -> ok end,
  
      ?assertEqual(undefined, whereis(?math_server)),
      ?assertNot(is_process_alive(ServerPid)),
  
negative.code: 
      sum_areas(Shapes, Client),
  
      receive after 4 ->
  		    ok
  	    end,
  
      exit(Client, unit_testing),
      aftereach().
  
  