// call by value - non-member function
RationalNumber operator/(const RationalNumber& one, const RationalNumber& two) {
	if (one.isNaN() || two.isNaN()) {
		RationalNumber r;
		return r;
	}
	RationalNumber r(one.nomi() * two.deno(), one.deno() * two.nomi());
	return r;
}
bool RationalNumber::operator==(const RationalNumber& other) const {
	if (other.isNaN())
		return false;

	signed short int a1 = nomi() * other.deno();
	signed short int b1 = deno() * other.deno();

	signed short int a2 = other.nomi() * deno();
	signed short int b2 = other.deno() * deno();

	return (a1 == a2 && b1 == b2);
}
bool RationalNumber::operator>(const RationalNumber& other) const {
	if (other.isNaN())
		return false;
	return ((nomi() * other.deno()) * (deno() * other.deno()))
			> ((other.nomi() * deno()) * (other.deno() * deno()));
}