

![0_image_0.png](0_image_0.png)

Now we add t to our achievable set, which thus becomes { s, t }.  The maximizer wins only if he really does win (and not just because he isn't interested in T any more), and the basic tree becomes:

![0_image_1.png](0_image_1.png)

What if the rightmost branch did not exist, so that the maximizer were unable to combine his chances? Now the value of the root node in the above tree is 0, so that {s,t} is not achievable. The maximal achievable set returned by the algorithm would be S ; had the