SplClassLoader e directory

[fermat]

allora, ho strutturato la cosa in maniera diversa.
dentro la root ho messo una directory service2 con questo dentro:

banca 
 |_index.php
libs 
 |_Slim 
 |_ |_App.php
 |_SplClassLoader.php

dentro index.php ho messo questo:

require_once '../libs/SplClassLoader.php';

$loader = new SplClassLoader('Slim', '/Slim');
$loader->register();
$app = new Slim\App();

$app->get('/', function ($request, $response, $args) {
    $response->write("Welcome to Slim!");
    return $response;
});

$app->get('/hello[/{name}]', function ($request, $response, $args) {
    $response->write("Hello, " . $args['name']);
    return $response;
})->setArgument('name', 'World!');

$app->run(); 

ma continuo ad ottenere errori:

Warning:  require(/Slim/Slim/App.php): failed to open stream: No such file or directory in /service2/libs/SplClassLoader.php on line 142

Warning:  require(/Slim/Slim/App.php): failed to open stream: No such file or directory in /service2/libs/SplClassLoader.php on line 142

Fatal error:  require(): Failed opening required '/Slim/Slim/App.php' (include_path='.:/php5.5/lib/php/') in /service2/libs/SplClassLoader.php on line 142