Re: MV Keys
Date: Tue, 07 Mar 2006 23:07:56 GMT
Message-ID: <gnoPf.6285$Rv1.1558_at_trndny07>
"Marshall Spight" <marshall.spight_at_gmail.com> wrote in message
news:1141745386.135572.24270_at_j33g2000cwa.googlegroups.com...
> x wrote:
> >
> > How do you know when you look at a set or at an element ? ;-)
>
> The RA does not have any operations for looking at elements. :-O
But the RA does rely on the existence of an operator that can test two
references to elements to see whether or not they refer to the same element.
You can't do all the RA operators, if you can't tell the elements apart.
Consider specifically the "project" operator. There is no way to implement
the project operator without "eliminating duplicates". There is no way to
eliminate the duplicates if you can't discern duplicates.
Received on Wed Mar 08 2006 - 00:07:56 CET