Returns the floating-point remainder r = x - n*y) when y is
    nonzero.
    This function is OpenVMS Alpha and Integrity servers only.
    Format
      #include  <math.h>
      double remquo  (double x, double y, int * quo);
      float remquof  (float x, float y, int * quo);
      long double remquol  (long double x, long double y, int * quo);
1 – Argument
 x
    A real number.
 y
    A real number.
 quo
2 – Description
    The remquo(), remquof(),  and remquol() functions compute
    the same remainder as the remainder(), remainderf(),  and
    remainderl() functions, respectively. In the object pointed to
    by quo, they store a value whose sign is the sign of x/y and
    whose magnitude is congruent modulo 2n to the magnitude of the
    integral quotient of x/y, where n is an implementation-defined
    integer greater than or equal to 3.
    The remquo functions are functionally equivalent to the remainder
    functions.
3 – Return Values
    r                  Upon successful completion, these functions
                       return the floating-point remainder r = x - ny
                       when y is nonzero.
    Nan                If x or y is Nan.