Re: Bijections (was OM = SIGMA1)

2007-11-20 Thread Bruno Marchal
Le 19-nov.-07, à 17:00, Torgny Tholerus a écrit : > Torgny Tholerus skrev: If you define the set of all natural numbers > N, then you can pull out the biggest number m from that set.  But this > number m has a different "type" than the ordinary numbers.  (You see > that I have some sort of "t

Re: Bijections (was OM = SIGMA1)

2007-11-20 Thread Bruno Marchal
Hi Mirek, Le 19-nov.-07, à 20:14, Mirek Dobsicek a écrit : > > Hi Bruno, > > thank you for posting the solutions. Of course, I solved it by myself > and it was a fine relaxing time to do the paper work trying to be > rigorous, however, your solutions gave me additional insights, nice. > > I am

Re: Bijections (was OM = SIGMA1)

2007-11-20 Thread Torgny Tholerus
Bruno Marchal skrev: > > To sum up; finite ordinal and finite cardinal coincide. Concerning > infinite "number" there are much ordinals than cardinals. In between > two different infinite cardinal, there will be an infinity of ordinal. > We have already seen that omega, omega+1, ... omega+omega

Re: Bijections (was OM = SIGMA1)

2007-11-20 Thread Bruno Marchal
Le 20-nov.-07, à 12:14, Torgny Tholerus a écrit : > > Bruno Marchal skrev: >> >> To sum up; finite ordinal and finite cardinal coincide. Concerning >> infinite "number" there are much ordinals than cardinals. In between >> two different infinite cardinal, there will be an infinity of ordinal. >>

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 -

Re: Bijections (was OM = SIGMA1)

2007-11-20 Thread meekerdb
Bruno Marchal wrote: > . > > But infinite ordinals can be different, and still have the same > cardinality. I have given examples: You can put an infinity of linear > well founded order on the set N = {0, 1, 2, 3, ...}. What is the definition of "linear well founded order"? I'm familiar with

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

Re: Bijections (was OM = SIGMA1)

2007-11-20 Thread Torgny Tholerus
Bruno Marchal skrev: > > But infinite ordinals can be different, and still have the same > cardinality. I have given examples: You can put an infinity of linear > well founded order on the set N = {0, 1, 2, 3, ...}. > The usual order give the ordinal omega = {0, 1, 2, 3, ...}. Now omega+1 > is

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 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 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 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