A Counterexample to a Theorem of Fu on Steiner´s Problem

In a paper by Fu it was stated that a necessary and sufficient condition to obtain a solution was found for Steiner´s problem with rectilinear distance. It was further claimed that a process of iteration which was presented leads to a solution. It is the purpose of this correspondence to give a counterexample to Fu´s main theorem and show that his iteration scheme does not always yield a solution. Hence Steiner´s problem remains unsolved in the general case.