/*
   This version seems to have a better chance, but still
   can't quite manage it
*/

#include "library.h"

double sum(const int from, const int to)
{ if (from <= to)
  { const double s = from*from - 10*from + 23;
    if (s < 0)
    { print("Error - square root of negative: ");
      print(s);
      print(" when i = ");
      print(from);
      new_line();
      return -1; }
    return sqrt(s) + sum(from + 1, to); }
  else
    return 0; }

void main()
{ print(sum(0, 10));
  new_line(); }