[uxcn]

I can see that a non-linear address space doesn't imply a strict weak ordering, but this still seems to be an implementation defined detail. It doesn't imply anything about pointer arithmetic overflow.

For example, consider x86 segments. Is there a reason why you would use negative offsets? Given a segment address, the number of representable values is identical whether the offset is strictly positive, or negative with a shifted segment address (assuming two's compliment).