By John S. McClenahen There's nothing Shermanesque about Federal Reserve Board Chairman Alan Greenspan's willingness to continue in that post. If nominated by President George Bush and confirmed by the Senate, he says he'd expect to serve. President Bush signaled last week that Greenspan "should" have another term as Fed chairman when his current term expires next year. In a subsequent statement, Greenspan noted that although he and Bush had not discussed reappointment, he greatly appreciated the President's confidence. "I have been privileged to be appointed by five presidents to various positions," said Greenspan. "If President Bush nominates me, and the Senate confirms his choice, I would have every intention of serving." A master of convoluted economic pronouncements -- they often leave people wondering what he really means -- Greenspan was remarkably clear and concise in his statement this time.