Jean, I read Chapter 6 of Calc as per your instructions, and found no problems with this entry. It appears to be quite consistant with comparable writings of this genre. At your request I scanned over the chapter quite quickly, looking for the glaring problems you were concerned about. I found no such issues with this chapter. And finally I read the document more thoroughly, looking for sintax issues, semantics problems and spelling and punctuation. Everything looks fine. Jerry
