# Re: sets of sets

From: Cimode <cimode_at_hotmail.com>
Date: 30 Jul 2006 13:03:38 -0700

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

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...

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

Original text of this message