Re: Cantor's Diagonal

2007-12-23 Thread Russell Standish
On Fri, Dec 21, 2007 at 01:08:38PM +0100, Günther Greindl wrote: > > Hi Russell, > > Russell Standish wrote: > > > In your first case, the number (1,1,1,1...) is not a natural number, > > since it is infinite. In the second case, (0,0,0,...) is a natural > > number, but is also on the list (at

Re: Cantor's Diagonal

2007-12-21 Thread Günther Greindl
Hi, > Because zero even repeated an infinity of time is zero and is a natural > number. (1,1,1,...) can't be a natural number because it is not finite and a > natural number is finite. If it was a natural number, then N would not have a > total ordering. Ok agreed: I was caught up in viewing

Re: Cantor's Diagonal

2007-12-21 Thread Quentin Anciaux
Hi, Le Friday 21 December 2007 13:08:38 Günther Greindl, vous avez écrit : > Hi Russell, > > Russell Standish wrote: > > In your first case, the number (1,1,1,1...) is not a natural number, > > since it is infinite. In the second case, (0,0,0,...) is a natural > > number, but is also on the list

Re: Cantor's Diagonal

2007-12-21 Thread Günther Greindl
Hi Russell, Russell Standish wrote: > In your first case, the number (1,1,1,1...) is not a natural number, > since it is infinite. In the second case, (0,0,0,...) is a natural > number, but is also on the list (at infinity). Why is (1,1,1,...) not in the list but (0,0,0,...) in the list at inf

Re: Cantor's Diagonal

2007-12-20 Thread Bruno Marchal
Le 19-déc.-07, à 21:09, Barry Brent a écrit : > > Excellent, Bruno, Thanks! Well thanks. I will send a next diagonalization post and some references next week, Best, Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received this message

Re: Cantor's Diagonal

2007-12-19 Thread Barry Brent
Excellent, Bruno, Thanks! Barry On Dec 19, 2007, at 7:57 AM, Bruno Marchal wrote: > > Hi Barry, > > > Le 18-déc.-07, à 18:52, Barry Brent a écrit : > >> >> Bruno-- >> >> Ahh, my amateur status is nakedly exposed. I'm going to expose my >> confusion even further now. > > > That is the courageou

Re: Cantor's Diagonal

2007-12-19 Thread Bruno Marchal
Hi Barry, Le 18-déc.-07, à 18:52, Barry Brent a écrit : > > Bruno-- > > Ahh, my amateur status is nakedly exposed. I'm going to expose my > confusion even further now. That is the courageous attitude of the authentic scientists. I like "amateur" because they have less prejudices, they have in

Re: Cantor's Diagonal

2007-12-18 Thread Barry Brent
Bruno-- Ahh, my amateur status is nakedly exposed. I'm going to expose my confusion even further now. Never heard of a universal language. I thought I was familiar with Church's thesis, but apparently no. I thought it was the claim that two or three or four concepts (including recursive

Re: Cantor's Diagonal

2007-12-18 Thread Bruno Marchal
Le 17-déc.-07, à 19:04, meekerdb (Brent Meeker) wrote: >> Bruno wrote: >> Exercise: >> What is wrong with the following argument. (I recall that by >> definition >> a function from N to N is defined on all natural numbers). >> >> (false) theorem: the set of computable functions from N to N is

Re: Cantor's Diagonal

2007-12-17 Thread meekerdb
ally kept up. > Anyway, I saw the reference to Cantor's Diagonal and thought perhaps > someone could help me. > > Consider the set of positive integers: {1,2,3,...}, but rather than > write them in this standard notation we'll use what I'll call 

Re: Cantor's Diagonal

2007-12-17 Thread Bruno Marchal
Hi Daniel, I agree with Barry, but apaprently you have still a problem, so I comment your posts. Le 16-déc.-07, à 10:49, Daniel Grubbs a écrit : > Hi Folks, > > I joined this list a while ago but I haven't really kept up.  Anyway, > I saw the reference to Cantor'

Re: Cantor's Diagonal

2007-12-16 Thread Barry Brent
Hi Dan, Let me take your statements a few at a time. >> Let me see if I am clear about Cantor's method. Given a set S, >> and some enumeration of that set (i.e., a no one-one onto map from >> Z^+ to S) we can use the diagonalization method to find an D >> which is a valid element of S b

Re: Cantor's Diagonal

2007-12-16 Thread Daniel Grubbs
any and all candidate enumerations. So you don't arrive at the absurdity you seem to be after, even if you fill in the details I mentioned. Barry On Dec 16, 2007, at 3:49 AM, Daniel Grubbs wrote: Hi Folks, I joined this list a while ago but I haven't really kept up. Anyway, I

Re: Cantor's Diagonal

2007-12-16 Thread Russell Standish
On Sun, Dec 16, 2007 at 04:49:34AM -0500, Daniel Grubbs wrote: Cantor's argument only works by finding a number that satisfies the criteria for inclusion in the list, yet is nowhere to be found in the list. In your first case, the number (1,1,1,1...) is not a natural number, since it is infinite

Re: Cantor's Diagonal

2007-12-16 Thread Barry Brent
e enumerations. So you don't arrive at the absurdity you seem to be after, even if you fill in the details I mentioned. Barry On Dec 16, 2007, at 3:49 AM, Daniel Grubbs wrote: > Hi Folks, > > I joined this list a while ago but I haven't really kept up. > Anyway, I saw

Re: Cantor's Diagonal

2007-12-16 Thread Daniel Grubbs
Hi Folks, I joined this list a while ago but I haven't really kept up.  Anyway, I saw the reference to Cantor's Diagonal and thought perhaps someone could help me. Consider the set of positive integers: {1,2,3,...}, but rather than write them in this standard notation we'l

Re: Cantor's Diagonal

2007-12-04 Thread Bruno Marchal
Le 03-déc.-07, à 16:56, David Nyman a écrit : > > On Nov 20, 4:40 pm, Bruno Marchal <[EMAIL PROTECTED]> wrote: > >> Conclusion: 2^N, the set of infinite binary sequences, is not >> enumerable. >> >> All right? > > OK. I have to try to catch up now, because I've had to be away longer > than I ex

Re: Cantor's Diagonal

2007-12-03 Thread David Nyman
On Nov 20, 4:40 pm, Bruno Marchal <[EMAIL PROTECTED]> wrote: > Conclusion: 2^N, the set of infinite binary sequences, is not > enumerable. > > All right? OK. I have to try to catch up now, because I've had to be away longer than I expected, but I'm clear on this diagonal argument. David > Hi,

Re: Cantor's Diagonal

2007-11-22 Thread Bruno Marchal
,...} > 4 {0,0,1,0,0,0,0,...} > 5 {1,0,1,0,0,0,0,...} > 6 {0,1,1,0,0,0,0,...} > 7 {1,1,1,0,0,0,0,...} > 8 {0,0,0,1,0,0,0,...} > ... > omega --- {1,1,1,1,1,1,1,...} > > What do we get if we apply Cantor's Diagonal to this

Re: elaboration Re: Cantor's Diagonal

2007-11-22 Thread Bruno Marchal
Le 22-nov.-07, à 07:19, Barry Brent a écrit : > > The reason it isn't a bijection (of a denumerable set with the set of > binary sequences): the pre-image (the left side of your map) isn't > a set--you've imposed an ordering. Sets, qua sets, don't have > orderings. Orderings are extra. (I'm

elaboration Re: Cantor's Diagonal

2007-11-21 Thread Barry Brent
ction: > > 0 {0,0,0,0,0,0,0,...} > 1 {1,0,0,0,0,0,0,...} > 2 {0,1,0,0,0,0,0,...} > 3 {1,1,0,0,0,0,0,...} > 4 {0,0,1,0,0,0,0,...} > 5 ---- {1,0,1,0,0,0,0,...} > 6 {0,1,1,0,0,0,0,...} > 7 {1,1,1,

Re: Cantor's Diagonal

2007-11-21 Thread Barry Brent
0,...} > 6 ---- {0,1,1,0,0,0,0,...} > 7 {1,1,1,0,0,0,0,...} > 8 {0,0,0,1,0,0,0,...} > ... > omega --- {1,1,1,1,1,1,1,...} > > What do we get if we apply Cantor's Diagonal to this? > > -- > Torgny > > > Dr. Barry Brent [EMAIL PROTECTE

Re: Cantor's Diagonal

2007-11-21 Thread Torgny Tholerus
,0,...} 4 {0,0,1,0,0,0,0,...} 5 {1,0,1,0,0,0,0,...} 6 {0,1,1,0,0,0,0,...} 7 {1,1,1,0,0,0,0,...} 8 {0,0,0,1,0,0,0,...} ... omega --- {1,1,1,1,1,1,1,...} What do we get if we apply Cantor's Diagonal to this? -- Torgny --~--~-~--~~--

Re: Cantor's Diagonal

2007-11-21 Thread Bruno Marchal
Le 21-nov.-07, à 08:49, Torgny Tholerus a écrit : > meekerdb skrev:Torgny Tholerus wrote: >> >>> >>> An ultrafinitist comment to this: >>> == >>> You can add this complementary sequence to the end of the list. That >>> will make you have a list with this complementary sequence included.

Re: Cantor's Diagonal

2007-11-21 Thread Bruno Marchal
Le 20-nov.-07, à 23:39, Barry Brent wrote : > > You're saying that, just because you can *write down* the missing > sequence (at the beginning, middle or anywhere else in the list), it > follows that there *is* no missing sequence. Looks pretty wrong to me. > > Cantor's proof disqualifies any

Re: Cantor's Diagonal

2007-11-21 Thread Bruno Marchal
Le 20-nov.-07, à 17:47, David Nyman a écrit : > > On 20/11/2007, Bruno Marchal <[EMAIL PROTECTED]> wrote: > >> David, are you still there? This is a key post, with respect to the >> "Church Thesis" thread. > > Sorry Bruno, do forgive me - we seem destined to be out of synch at > the moment. I'm

Re: Cantor's Diagonal

2007-11-20 Thread Torgny Tholerus
meekerdb skrev: Torgny Tholerus wrote: An ultrafinitist comment to this: == You can add this complementary sequence to the end of the list. That will make you have a list with this complementary sequence included. But then you can make a new complementary sequence, that is

Re: Cantor's Diagonal

2007-11-20 Thread Barry Brent
You're saying that, just because you can *write down* the missing sequence (at the beginning, middle or anywhere else in the list), it follows that there *is* no missing sequence. Looks pretty wrong to me. Cantor's proof disqualifies any candidate enumeration. You respond by saying, "we

Re: Cantor's Diagonal

2007-11-20 Thread meekerdb
Torgny Tholerus wrote: > Bruno Marchal skrev: >> But then the complementary sequence (with the 0 and 1 permuted) is >> also well defined, in Platonia or in the mind of God(s) >> >> *0* *1* *1* *0* *1* *1* ... >> >> But *this* infinite sequence cannot be in the list, above. The "God" >> in questi

Re: Cantor's Diagonal

2007-11-20 Thread Torgny Tholerus
Bruno Marchal skrev: But then the complementary sequence (with the 0 and 1 permuted) is also well defined, in Platonia or in the mind of God(s) 0 1 1 0 1 1 ... But this infinite sequence cannot be in the list, above. The "God" in question has to ackonwledge that. The complemen

Re: Cantor's Diagonal

2007-11-20 Thread David Nyman
On 20/11/2007, Bruno Marchal <[EMAIL PROTECTED]> wrote: > David, are you still there? This is a key post, with respect to the > "Church Thesis" thread. Sorry Bruno, do forgive me - we seem destined to be out of synch at the moment. I'm afraid I'm too distracted this week to respond adequately -

Cantor's Diagonal

2007-11-20 Thread Bruno Marchal
Hi, David, are you still there? This is a key post, with respect to the "Church Thesis" thread. So let us see that indeed there is no bijection between N and 2^N = 2X2X2X2X2X2X... = {0,1}X{0,1}X{0,1}X{0,1}X... = the set of infinite binary sequences. Suppose that there is a bijection between N