/* June 17, 1998 */
/* rewrite a program using pointer to a program using function */
/* pg 285 number 1 */

#include <stdio.h>

/* function prototype */
int sum(int a, int b);

main ()
{

	/* declaration */
	int x, y, z;

	/* assign values */
	x = 5; y = 3;

	printf("   x   y   z\n\n");

	printf("%4d%4d%4d\n", x, y, sum(x,y));

        printf("%4d%4d%4d\n", x, y, sum(y, x));

        printf("%4d%4d%4d\n", sum(sum(x,y), y) , y, sum (x, y));	

        printf("%4d%4d%4d\n", sum(sum(x, y), sum(x ,y)), y, sum(x, y));

        printf("%4d%4d%4d\n", sum(sum(x ,y), sum(x, y)), sum(y, y), 
sum(x,y)); }


/* function defintion */
int sum(int a, int b)
{
	/* local variable */
	int c;

	return(c = a + b);

}