Re: repeating groups

From: JOG <jog_at_cs.nott.ac.uk>
Date: 20 Feb 2006 17:58:41 -0800
Message-ID: <1140487121.518363.37680_at_g47g2000cwa.googlegroups.com>


mAsterdam wrote:
> JOG wrote:
>
> > This discussion is extremely interesting.
>
> Yep. It is also tricky, and there is a minefield of
> of hidden terminology differences. If we want to get somewhere,
> we'll have to iron out ambiguities. I really don't want to
> reduce the discussion to just vocabulary stuff - it's just
> that I've seen so many misunderstandings due to different
> habits of using words for similar things. This topic
> just requires some special care in the choice of words.
>
> I'll take your sentence below as an example - not wanting to
> dismiss your post in any way.
>
> > It relates to my own area,
> > and I firmly believe it is a promising source of development. Sets and
> > lists (ordered sets) underly almost all of modern mathematics, yet
> > current DB models surely throw only cursory regard to this (and often
> > exaggerate their attempts to do so).
>
> "lists (ordered sets)"
>
> Are they the same? No.
> Lists may have duplicate items, ordered sets may not.
>
> [snip]

you are of course correct - lists are ordered multisets. Received on Tue Feb 21 2006 - 02:58:41 CET

Original text of this message