# Re: sets of sets

Date: 30 Jul 2006 13:03:38 -0700

Message-ID: <1154289818.452194.142430_at_b28g2000cwb.googlegroups.com>

This paper was discussed and proposed by Aloha in the following thread...

http://groups.google.com/group/comp.databases.theory/browse_frm/thread/92e6d4ca5baf9266

It is an introductary paper on ensemblist math..The paper was linked on

http://arxiv.org/PS_cache/cs/pdf/0607/0607039.pdf

http://www.amazon.fr/exec/obidos/ASIN/3540225250/403-4729874-1286004

In words (source wilkipedia)

"Given any set A, there is a set such that, given any set B, B is a
member of if and only if B is a subset of A"

A direct application for RM was evocated in the thread I mentionned...

Check the below link for more info...

http://en.wikipedia.org/wiki/Axiom_of_power_set

Hope this helps...

[Quoted] paul c wrote:

> I'm trying to read a recent paper I found at

*> http://csr.uvic.ca/~vanemden/Publications/STPCS.pdf
**>
**> (The description intrigued me because the author is exploring RT. I'll
**> try to contact the author with my question, but I thought I'd mention it
**> here as others may be interested.)
**>
**> Anyway, at the top of page 5, he defines something I can only call
**> "UNION S" (since I don't know know how to type the set union operator
**> symbol).
**>
**> Can anybody suggest whether I'm reading it right? What I think it says
**> in prose is "the set of x such that x is a member of some subset of S".
**>
**> Below I've tried to paste the pdf text, not sure how it will show up in
**> different newsreaders, sorry for breaking the rules with a little bit of
**> non-text:
**>
**> Let S be a nonempty set of sets. Then ∪S is defined as {x | ∃S′ ∈ S . x
**> ∈ S′} ...
**>
**> Then he mentions what I call "INTERSECTION S" which seems to mean the
**> set of x such that x is a member of all subsets of S", (text pasted
**> below, I hope):
**>
**> and ∩S as {x | ∀S′ ∈ S . x ∈ S′}.
**>
**> p
*

Received on Sun Jul 30 2006 - 22:03:38 CEST