#include<math.h>

/* How to define static?
 * "Restricted in scope"
 */

/* Static means this function is only available in this file */
static double fred(double z){
	return 3*z;
}

double bob(double z){
	return round(fred(z))/3;
}

int counter(){
	/* This means count is a global, but restricted to this function */
	static int count = 0;
	return count++;
}