Call to undefined function validation ()

I am converting to codeigniter 4
In a sub view I want to show all the errors of the form. In codeigniter 3 I was using validator_errors without problems

In the BaseController I loaded the Validation livery

PHP Code:

$this->validation = \Config\Services::validation (); 


In the subview it is, while the errors see exist:

PHP Code:

if (! empty (validation () -> listErrors ()))
    echo validation () -> listErrors 


I get the error

Code:

Call to undefined function validation ()