The PrOp is certainly improvable in detail; and detailed suggestions for its improvement are made and accepted routinely.
It is not, however, an HLASM textbook. It is a reference work; and it should, I think, remain so. If Melvyn needs a textbook for his assemby-language students and none of those already available meets his|their needs, he should write a new one that does so. John Gilmore, Ashland, MA 01721 - USA
