NAG Library Manual, Mark 27.3
```/* D01RM_P0W_F C++ Header Example Program.
*
* Copyright 2021 Numerical Algorithms Group.
* Mark 27.3, 2021.
*/

#include <iostream>
#include <math.h>
#include <nag.h>
#include <stdio.h>
using namespace std;

int main()
{
// Scalars
int exit_status = 0;

cout << "D01RM_P0W_F C++ Header Example Program Results\n\n";

double bound, epsabs, epsrel;
bound  = 0.0;
epsabs = 0.0;
epsrel = 1.0e-4;

Integer  inf    = 1;
Integer  maxsub = 20;
Integer  lrinfo = 80;
Integer  liinfo = 20;
double * rinfo  = 0;
Integer *iinfo  = 0;

rinfo = new double[lrinfo];
iinfo = new Integer[liinfo];

double            inc = 1.0;
double            result, abserr, ruser[22];

for (int i = 0; i < 20; ++i)
{
ruser[i] = 0.0;
}
ruser[20] = 1.0;
ruser[21] = 1.0;

const double *x,
const Integer &         nx,
double *fv,
Integer &               iflag)
{
// dco/c++ used here to perform AD of the following
for (int i = 0; i < nx; i++)
{
fv[i] = 1.0 / ((x[i] + ruser[20]) * sqrt(ruser[21] * x[i]));
}
};

// Call the passive routine
Integer ifail = -1;
abserr, rinfo, iinfo, ifail);
if (ifail < 0)
{
cout << "\n ** nag::ad::d01rm failed error exit ifail = " << ifail << endl;
goto END;
}
// Print inputs and primal outputs.
cout << "\n lower limit of integration (bound) = " << bound << endl;
cout << " upper limit of integration (Inf)   = "
<< "Infinity" << endl;
cout << " absolute accuracy requested    = " << epsabs << endl;
cout << " relative accuracy requested    = " << epsrel << endl;
cout << " maximum number of subintervals = " << maxsub << endl;
cout.setf(ios::scientific, ios::floatfield);
cout.precision(4);
if (ifail >= 0)
{
cout << "\n approximation to the integral  : " << result << endl;
cout << " estimate of the absolute error : " << abserr << endl;
cout << " number of function evaluations : " << iinfo[0] << endl;
}

END:

delete[] rinfo;
delete[] iinfo;
return exit_status;
}
```