#include <stdio.h>
 
double f (double x);
int sameSign(double x, double y);
double middleOf(double x, double y);
int isSmallNumber(double x);

/* Just ugly */
double findRootBetween(double a, double b)    {
    double l = a,
  u =   b   ;
    while    (!isSmallNumber(f(middleOf(l, u)))) { 
  if(sameSign(f(middleOf(l, u)), f(u)))
              u = middleOf(l,u);
      else 
            l = middleOf(l,   u);
    }
    return
        middleOf(l,
 u);
}  

int main (void)
{
    findRootBetween(-3.0, 
                    5.0);}