(b) Show that finding a feasible solution for the original network is equivalent to finding
the maximal flow xi; in the network after (1) modifying the bounds on Xi; to
o ::5 xi; ::5 Ui; - ii;, (2) "lumping" all the resulting sources into one supersource with
outgoing arc capacities li;' (3) "lumping" all the resulting sinks into one supersink
with incoming arc capacities li;' and (4) connecting the terminal node t to the source
node s in the original network by a return infinite-capacity arc. A feasible solution
exists if the maximal flow in the new network equals the sum of the lower bounds in
the original network. Apply the procedure to the following network and find a feasible
flow solution:
after lumping