NAG Library Manual, Mark 27.2
```/* nag_specfun_hyperg_confl_real (s22bac) Example Program.
*
* Copyright 2021 Numerical Algorithms Group.
*
* Mark 27.2, 2021.
*/

#include <nag.h>
#include <stdio.h>
#include <string.h>

void construct_table(double a, double b);

int main(void) {
/* Scalars */
Integer exit_status = 0;
Integer kx;
double a, b, m, x;
/* Nag Types */
NagError fail;

INIT_FAIL(fail);

printf("nag_specfun_hyperg_confl_real (s22bac) Example Program Results\n\n");

a = 13.6;
b = 14.2;

construct_table(a, b);

for (kx = -5; kx < 6; kx++) {
x = (double)kx + 0.5;
/* Evaluate Real confluent hypergeometric function M(a,b,x) using
* nag_specfun_hyperg_confl_real (s22bac).
*/
nag_specfun_hyperg_confl_real(a, b, x, &m, &fail);
printf("%13.2f  ", x);
switch (fail.code) {
case NE_NOERROR:
case NW_UNDERFLOW_WARN:
case NW_SOME_PRECISION_LOSS: {
printf("%13.5e\n", m);
break;
}
default: {
printf("No finite or sufficiently accurate result.\n");
exit_status = 1;
break;
}
}
}
return exit_status;
}

void construct_table(double a, double b) {
printf("          a              b\n");
printf("+--------------+--------------+\n");
printf("%13.2f  %13.2f\n", a, b);
printf("+--------------+--------------+\n");
printf("          x        M(a,b,x)\n");
printf("+--------------+--------------+\n\n");
return;
}
```