Re: Proposal: 6NF

vc wrote:
> 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) ;) ?

Call it integer division to distinguish it from the real division? :-)

• Jan Hidders