Exercise 12.28 Find the communicating classes, and the closed communicating classes, when the transition matrix is P =





1 2 0 0 0 1 2

0 1 2 0 1 2 0 0 0 1 0 0 0 1 4

1 4

1 4

1 4

1 2 0 0 0 1 2





.

It may be useful to draw a diagram.