Re: Is {{}} a valid construct?

"David Marcus" <DavidMarcus_at_alumdotmit.edu> wrote in message news:MPG.202db54e36fa45ec989c26_at_news.rcn.com...
> Neo wrote:
> > > > > > Can an empty set contain an empty set?
> > >
> > > > > If a set contains an element, be it the empty set or not,
> > > > > its not the empty set.
> > > > > So put your one empty bag of potatoes into your other
> > > > > empty bag of potatoes. And wush your second bag is not
> > > > > empty anymore. You see, it contains the first empty bag.
> > >
> > > > Thanks, however I am still confused as Bod Badour in
> > > > comp.database.theory has the following reply to your post:
> > >
> > > The two answers say the same thing.
> >
> > Do'h! time to untunnel my vision B(
> >
> > > Why are you confused?
> >
> > Prior to putting one bag inside the other, there were two empty bags
> > meaning two empty sets. How could this be? Set theory says otherwise.
>
> Because a bag is a metaphor, not a set.

While this is a typical witless dialogue between Neo (a person pretending to be a droid, or vice versa) and some reasonable people, I couldn't help responding to this one thing you said.

It's important to realize that every symbol inside a computer is a metaphor. A transparent zone is a metaphor for a zero, and an opaque zone is a metaphor for a one (on an optical disk). As we proceed up the levels of abstraction from there, it's all metaphor.

Not that this has any bearing on the question Neo keeps asking. I just thought it would be worth calling attention to it in passing. Received on Mon Feb 05 2007 - 21:15:12 CET