A = [8 1 6; 3 5 7; 4 9 2];
A([3,4,5,6]) = [4 1 5 9] A([3;4;5;6]) = [4;1;5;9]
A([3,4,5,6]) = [3 4 5 6] A([3;4;5;6]) = [3;4;5;6]
A([3,4,5,6]) = [4;1;5;9] A([3;4;5;6]) = [4 1 5 9]
A([3,4,5,6]) = [3;4;5;6] A([3;4;5;6]) = [3 4 5 6]