Question: Derive Theorem I from Theorem II.
Theorem I: An upper-bounded transshipment problem has no feasible solution if and only if there is a set S of nodes such that
THEOREM II: (The Max-Flow Min-Cut Theorem). Every maximum-flow I problem has precisely one of the following two properties:
(i) There are feasible flows of arbitrarily large volumes and every cut has an infinite capacity.
(ii) There is a maximum flow and its volume equals the minimum capacity of a cut.