public function Program()
 {
     $a = array(3, 4, 5);
     $b = array(4, 3, 5);
     $c = array(-5, -12, -13);
     $va = new Vector($a);
     $vb = new Vector($b);
     $vc = new Vector($c);
     $result1 = Vector::dotProduct($va, $vb);
     $result2 = Vector::crossProduct($va, $vb)->getValues();
     $result3 = Vector::scalarTripleProduct($va, $vb, $vc);
     $result4 = Vector::vectorTrippleProduct($va, $vb, $vc)->getValues();
     printf("\n");
     printf("A = (%0.2f, %0.2f, %0.2f)\n", $a[0], $a[1], $a[2]);
     printf("B = (%0.2f, %0.2f, %0.2f)\n", $b[0], $b[1], $b[2]);
     printf("C = (%0.2f, %0.2f, %0.2f)\n", $c[0], $c[1], $c[2]);
     printf("\n");
     printf("A · B = %0.2f\n", $result1);
     printf("A × B = (%0.2f, %0.2f, %0.2f)\n", $result2[0], $result2[1], $result2[2]);
     printf("A · (B × C) = %0.2f\n", $result3);
     printf("A × (B × C) =(%0.2f, %0.2f, %0.2f)\n", $result4[0], $result4[1], $result4[2]);
 }