The parliamentary system can be contrasted with a presidential system , such as the American congressional system , which operates under a stricter separation of powers , whereby the executive does not form part of .
It part not appointed by , the parliamentary or legislative body .
The parliamentary system can be contrasted with a presidential system , such as the American congressional system , which operates under a stricter separation of powers , whereby the executive does not form part of , nor is it appointed by , the parliamentary or legislative body .