Is º an unicode alphabetic character?

[AsmMan via Digitalmars-d-learn]

Thanks Ali, I think I get close:

bool is_id(dchar c)
{
	return c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c >= 0xc0 
&& c <= 0x0d || c >= 0xd8 && c <= 0xf6 || c >= 0xf8 && c <= 0xff;
}

this doesn't include some math symbols. like c >= 0xc0 did.