Thanks. I'm not sure I agree as to compatibility issues, but that is probably because I find that certain software vendors (IBM) often make poor design choices and then we are stuck with them "forever" because of having to be compatible. DEC's TOPS-20 operating system had a neat feature that allowed a file to have a version number. One could reference a file without a version number and always get the most recent (highest number) version. Opening for output always created a new version unless the version was specifically requested. This file system allowed a subroutine to be referenced either generically, or by specific version. Combining this concept with management practice that maintained incompatible versions, the compatibility issues would be less severe, allowing (hopefully) for greater progress in software sophistication. Too bad IBM did not adopt something like this. The multiple X-To has been seen only on SOME mail, less than half. My ListServ is on 1.5b I think (it says it is). I still have not gotten hold of the person in the graduate admissions office here who handles foreign student admission. I have gone ahead and sent to you by snail mail (postal delivery) the Graduate Programs Catalog and the Catalog of Course for University of Illinois/UC.