Re: Proposal: 6NF

Jan Hidders wrote:
> vc wrote:
> >
> > More interestingly, why bother with a trivial fact that Z may be
> > [considered] a subset of R in whatever sense ?
>
> Because you want a simple formalization of subtyping a la Cardelli and
> Wegner where subtyping coincides with being a subset. It means that the
> meanig of the + operation in (a + b) can be considered independent of
> the type of a and b.

RIght, but my understanding of the OOP stuff leads me to believe that a subtype should '"inherit" its type operations. If so, assuming R is our base type, what do we do about division in Z (regarded as an R subtype) ;) ?

>
> -- Jan Hidders
Received on Fri Oct 13 2006 - 17:22:08 CEST