Exercise 9.5. Consider a modified Max Flow problem in which the underlying network is undirected so flow in each edge can go either way. Show that each instance of this problem can be reformulated to a normal Max Flow instance. Note that this allows us to solve this modified Max Flow problem using Ford-Fulkerson Exercise 9.5. Consider a modified Max Flow problem in which the underlying network is undirected so flow in each edge can go either way. Show that each instance of this problem can be reformulated to a normal Max Flow instance. Note that this allows us to solve this modified Max Flow problem using Ford-Fulkerson