Default value of form validation when not validation control

[eluser]Unknown[/eluser]
Dear all,

what is default value of form validation, if doesn't validate any control ?
It true or false?

ACTION when click submit button.

$this->load->helper(array('form', 'url'));
$this->load->library('form_validation');
if ($this->validation->run() == FALSE) {

echo "fail";

} else {

echo "formsuccess";

}