Slim router with functions

I got this code

$app->post('/crear', 'Autenticar', function() use ($app) {}

And I want to make it clear, so I decided to write the following


So, in the CrearRegistro function I must verify that the user is logged, that function is made by the Autenticar function, that is the second argument on the first routing. My problem is how to pass the Autenticar function to the CrearRegistro function.