4.b The values of the non-terminal nodes are now estimated by an unknown function . Assume that the function gives the correct minimax value of a non-terminal node to within 2, that is, 2 the true minimax value +2. With this assumption, cross off the leaf nodes that will be pruned by Alpha-Beta pruning (assume the leaf nodes are visited from left to right). Assume that the values of non-terminal nodes in the figure are known before visiting any leaf node. Show the derivation procedure on the graph. .