Function extern_spec_SubAssign_u8_u8_sub_assign 

pub fn extern_spec_SubAssign_u8_u8_sub_assign(self_: &mut u8, rhs: u8)

extern spec for u8::sub_assign

This is not a real function: its only use is for documentation.

requires

$type::MIN@ <= self@ $op rhs@ && self@ $op rhs@ <= $type::MAX@

ensures

(^self)@ == self@ $op rhs@