x33 = [1, 1, 1; 1, 1, 1; 1, 1, 1];
x23 = [1, 1, 1; 1, 1, 1];
(ones (3) == x33 && ones (size (x33)) == x33 && ones (3, 3) == x33
 && ones (2, 3) == x23 && ones (3, 2) == x23')
