Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » sci.math.* » sci.math

Topic: Weierstrass
Replies: 26   Last Post: Jul 9, 2004 4:27 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
David W. Cantrell

Posts: 3,395
Registered: 12/3/04
Re: Weierstrass
Posted: Jul 9, 2004 6:28 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply


jesse@phiwumbda.org (Jesse F. Hughes) wrote:
> Eckard Blumschein <blumschein@et.uni-magdeburg.de> writes:
>

> > Robin Chapman wrote:
> >

> >>>I realized: An empty set is known to be neither open nor closed, of
> >>>course.

> >>
> >>
> >> !

> >
> > http://mathworld.wolfram.com/EmptySet.html
> >
> > Well, they did not write "neither not" but "both" open and closed.
> > Since open and close contradict each other, I was just a bit sloppy.

>
> But the topological notions don't contradict each other at all.
>
> I'm not sure that I'd call your statement above "just a bit sloppy".
> If X and Y are true, then asserting "NOT X and NOT Y" is more than a
> bit sloppy.
>

> > I merely do not understand why they wrote "strangely".
>
> Me either.


I suspect I do: Eric Weisstein wrote "strangely" because the words "open"
and "closed" _seem_, based on their extramathematical meanings, to
contradict each other.

David




Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.