The parentheses don't have an impact on the Nemeth Code's definition of a complex or hypercomplex fraction.
You have three fractions here.
--The first one (the anchor) is a simple fraction. The words in the numerator and the denominator will be uncontracted.
--The second fraction (the first link) is a complex fraction.
--The third fraction (the second link) contains the simple fraction "r over n".
The Nemeth Code defines "complex fraction" as follows. A complex fraction is one whose numerator, denominator, or both, contains at least one simple fraction.
It goes on to say that a fraction is not a complex fraction if the only simple fractions it contains are at the superscript or subscript level. That is not the case with your example.
There are no hypercomplex fractions in the expression. To be a hypercomplex fraction, the numerator, denominator, or both, must contain at least one complex fraction.
The complex fraction indicators and fraction line start with one dot 6.