Rational numbers P50688

Define a @rational@ type, to operate with rational numbers and implement the following operations:

    rational zero (); 
    rational fixa (int num, int den);
    
    int numerator ();
    int denominator ();

    rational sum (rational q1, rational q2);
    rational sub (rational q1, rational q2);
    rational mul (rational q1, rational q2);
    rational div (rational q1, rational q2);
    
    double real (rational q);
    
    void print (rational q);
    

Observation

You only need to submit the required procedure; your main program will be ignored.