Phil Nelson wrote:

Another problem ... it will make pred() and succ() harder if they must do succ(Greater) => Strange and pred(Strange) => Greater. I think setting the initial value would be reasonable, but not allowing a jump in the values.

Another possibility would be to let succ (and inc) just increase the ordinal value by 1, then test (with the generic range checking procedure) if it's a valid ordinal value. I'm not sure if succ/inc are supposed to work this way or the other, what does the standard say? -- Frank Heckenbach, Erlangen, Germany heckenb@mi.uni-erlangen.de Turbo Pascal: http://www.mi.uni-erlangen.de/~heckenb/programs.htm Internet links: http://www.mi.uni-erlangen.de/~heckenb/links.htm