Letter to the Editor—Remarks on Network Simplification

In “The Use of Wye-Delta Transformations in Network Simplification,” Sheldon B. Akers, Jr. stated two conditions that together were supposedly sufficient for the validity of delta-wye transformations on networks with finite vertex capacities. This letter gives a counterexample to the sufficiency of the two conditions and demonstrates the necessity of the first condition to delta-wye transformations.