Re: Relation Definition

From: Dawn M. Wolthuis <dwolt_at_tincat-group.comREMOVE>
Date: Wed, 23 Feb 2005 13:17:00 -0600
Message-ID: <cvikrg$28d$1@news.netins.net>

"Jan Hidders" <jan.hidders_at_REMOVETHIS.pandora.be> wrote in message news:_24Td.19245$Ix6.2454622_at_phobos.telenet-ops.be...
> Anith Sen wrote:

<snip>
>> Even being a standard definition, its usage may not obviated in a
>> relational definition. See, you stated the usage of n-dimensional notion
>> as inappropriate while defining relations and some
>> justification for that statement would be helpful.
>
> Er, no, that's not exactly what I claimed. Here's what I really said:
>
> Jan Hidders wrote:
>> The notion of n-dimensional tuple is usually reserved for ordered
>> tuples which is not appropriate here.
>
> The "which" in that sentence refers to "ordered tuples" and not to
> "n-dimensional tuple". I have no problem with the usage of that term as
> long as it is explicitly stated that we are talking about unordered
> tuples and what those precisely are.

As data structures, unordered tuples would be bags/multisets (and possibly sets), is that correct? The reason not to call them that is because of the additional information about the domain from which each element comes, perhaps? Otherwise I don't "get" the use of the term "tuple" when there is no ordering. --dawn

> -- Jan Hidders
Received on Wed Feb 23 2005 - 13:17:00 CST