max(), sum(), next()

[castironpi]

On Sep 5, 3:28 am, "Manu Hack" <manuh... at gmail.com> wrote:
> On Thu, Sep 4, 2008 at 4:25 PM, castironpi <castiro... at gmail.com> wrote:
> > On Sep 4, 2:42 pm, bearophileH... at lycos.com wrote:
> >> David C. Ullrich:
>
> >> > At least in mathematics, the sum of the elements of
> >> > the empty set _is_ 0, while the maximum element of the
> >> > empty set is undefined.
>
> >> What do you think about my idea of adding that 'default' argument to
> >> the max()/min() functions?
>
> >> Bye,
> >> bearophile
>
> > For max and min, why can't you just add your argument to the set
> > itself?
>
> > The reason max([]) is undefined is that max( S ) is in S.
>
> It makes sense.
>
> >The reason sum([]) is 0 is that sum( [ x ] ) - x = 0.
>
> It doesn't make sense to me.  What do you set x to?

For all x.