/***************************************
 * add-func.c                          *
 * 2 つの double 型数の和を返す関数の使用例 *
 ***************************************/
#include <stdio.h>
double add(double x, double y);

int main(void)
{
    double a;

    a = add ( 1.2, 2.3 );
    printf("a = %f\n", a );

    return 0;
}

double add(double x, double y)
{
    double z;

    z = x + y;

    return z;
}