Re: So what's null then if it's not nothing?

Alexandr Savinov wrote:
> Jon Heggland schrieb:
> > In article <1134926774.703015.67240_at_z14g2000cwz.googlegroups.com>,
> > boston103_at_hotmail.com says...
> >
> >>Sure, a one-argument predicate like 'is_null', or 'is_odd', talks
> >>about a property/attribute and can be called an 'adjective'. But the
> >>'is_null' predicate cannot help one answer the question "what is '+' in
> >>'2 + NULL' ?". So, what is '+' in the expression and how does one
> >>interpret such expression ?
> >
> >
> > "2 + NULL" isn't a valid expression. (Well, it is in SQL(?), but I don't
> > think it should be, and I won't try to justify it.)
>
> 2 + NULL = 2
OK.

>
> Just remove NULL because it is a flag to denote a non-existing thing
> (which exists in other dimensions but does not exist here in the current
> dimension). So there are neither formal nor informal problems with this
> expression if we provide correct interpretation of NULL. Notice that
> NULL here (and always) in not number 0. In the expression 2+NULL we do
> not apply the operation at all,

How do you reconcile '2 + NULL = 2' with "In the expression 2+NULL we do not apply the operation at all" ?

>while in 2+0 we do apply the sum operation.
>
> --
> http://conceptoriented.com
Received on Mon Dec 19 2005 - 12:24:06 CET