1
   

Cantor's Theorem

 
 
Reply Sat 2 Jul, 2005 03:36 pm
Hi everyone.

I'm trying to show that the following inequality holds in ZFC:

w(w) < [w(w)]^w

where w(w) means omega-subscript-omega, and [w(w)]^w means omega-subscript-omega raised to the power omega.

I don't have a problem showing that the non-strict inequality holds, but I am having a hard time showing that the two are not equal. I know that doing so involves adapting the proof of Cantor's Theorem (i.e. using a diagonalization argument) but I'm having a hard time figuring out how to do that.
  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Discussion • Score: 1 • Views: 514 • Replies: 2
No top replies

 
raprap
 
  1  
Reply Mon 4 Jul, 2005 03:51 pm
Cantor's thm sets a cardinality to infinity, e.g. all infinities are not equal. As an example consider integers, they go from a negative infinity integer to a positive integer infinity so the set has an infinite number of elements.

But is there a 1 to 1 relation between the elements in the set of integers and the elements in the set of rational numbers? Cantor argued that an infinite number of rational elements existed between any two integer set elements. So the answer was no, the infinity of the set of integers was smaller (had a smaller cardinality) than the set of rational numbers. The set of rational numbers had a higher cardinality (aelph) than the set of integers.

The same can be said of the set of irrationals over rationals, and the set of imaginarys over irrationals.

Now to your problem---I really don't understand the fixation with Cantor

I see the following condition
if w(w)>1
then
w(w)<w(w)^n if n<1
w(w)=w(w)^n if n=1
w(w)>w(w)^n if n>1

if w(w)=1
then
w(w)=w(w)^n for all n

if w(w)<1
then
w(w)>w(w)^n if n<1
w(w)=w(w)^n if n=1
w(w)<w(w)^n if n>1

Rap
0 Replies
 
greatwhiteshark
 
  1  
Reply Mon 4 Jul, 2005 08:10 pm
HeyThank You
You are very nice to help me as you do. I like your notes.
0 Replies
 
 

Related Topics

Evolution 101 - Discussion by gungasnake
Typing Equations on a PC - Discussion by Brandon9000
The Future of Artificial Intelligence - Discussion by Brandon9000
The well known Mind vs Brain. - Discussion by crayon851
Scientists Offer Proof of 'Dark Matter' - Discussion by oralloy
Blue Saturn - Discussion by oralloy
Bald Eagle-DDT Myth Still Flying High - Discussion by gungasnake
DDT: A Weapon of Mass Survival - Discussion by gungasnake
 
  1. Forums
  2. » Cantor's Theorem
Copyright © 2025 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.04 seconds on 01/22/2025 at 12:44:57