What is the Collatz Problem and how can it be solved?

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The discussion centers on the Collatz problem and the implications of fixing the variable k within its mathematical framework. Participants debate whether k should be considered fixed or variable, with arguments suggesting that treating k as fixed leads to contradictions in the proof structure. The concept of decidability is also scrutinized, with claims that the Collatz problem is undecidable due to its reliance on the axioms of infinity and the inherent symmetry of the Binary Tree. The conversation highlights the complexity of proving the Collatz conjecture and the necessity of clarifying terms like "out of range" and "fixed" in mathematical discourse. Ultimately, the participants emphasize the need for rigorous definitions and logical consistency in mathematical proofs related to the Collatz problem.
  • #241
Originally posted by Organic
Matt,

Is it beyond you ability to understand that my matrix power_value = |N|?

Would it be beyond you to define what that sentence means? Apparently, yes.

You state the case for 2^n, then make a statement about 2^|N|. Fine but you cannot conclude anything about that case by induction or iteration from the finite case, not that you even bother to do that. In particular you cannot conclude that the information can be written encoded in a matrix with countable sets of rows and columns. One does not logically follow from the other (it is false, we have proved it).
 
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  • #242
Matt,
Why would that help? If you've made this construction surely you know how you made it? How come you get to be so sure of yourself and that Hurkyl and I are wrong and don't understand when you don't even know the meaning of the terms you use?
Is it beyond your ability to understand that my matrix power_value = |N|?

It is very easy because there is a bijection between the power_values and N members.
 
  • #243
So there is a bijection from the set

{2^n | n in N} and N.

So?

Or do you mean there is a bijection from a set of cardinality 2^|N| and N? Well, there isn't. Check the above post where I ask you if it is beyond you te even define what it means ot have power value |N|

so for the god knows how manyth time, write down the construction that enables you to write these matrices out and make the claims you do.
 
  • #244
Matt,

Maybe this will help you:

Please tell me if you understand the set that I wrote below
Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
[b]{[/b]...,1,1,1,1[b]}[/b] 
 ...,1,1,1,0  
 ...,1,1,0,1  
 ...,1,1,0,0  
 ...,1,0,1,1  
 ...,1,0,1,0  
 ...,1,0,0,1  
 ...,1,0,0,0  
 ...,0,1,1,1  
 ...,0,1,1,0  
 ...,0,1,0,1  
 ...,0,1,0,0  
 ...,0,0,1,1  
 ...,0,0,1,0  
 ...,0,0,0,1  
 ...,0,0,0,0  
 ...

It is also can be written as: {10... ,1100... ,11110000... ,...}
 
Last edited:
  • #245
That does not help because you do not explain what the ellipsis of the ... means.here is what I think it means (again, for pity's sake, why do you refuse to answer simple direct questions and observations)

we start with the two diagrams in your newdiagonal pdf that you eunmerate, the left hand one

the columns go
..0000
..0001
..0010
..0011
..0100
..0101
...
...
...
...where the first column is based on repeatin the pattern 01, the second by repeating the pattern 0011 the rth by repeating 2^r 0s then 2^r 1s (each pattern repeating infinitely many times in the column, so that you cannot claim I think it's finite, and for r goes from 1 to infinity)

now the second diagram is the first but every entry above the diagonal is a 1you now interleave these rows alternating one from each.Is that accurate?
 
  • #246
Matt,

It is also can be written as: {10... ,1100... ,11110000... ,...}

... means that each 0 1 starting repeats on itself forever.
 
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  • #247
But is my characterization equivalent to yours?
 
  • #248
I think he's looking at the set of columns, and assuming it's obvious that when he writes "..." he means "repeat that string of digits indefinitely"
 
  • #249
Originally posted by Organic
Matt,

It is also can be written as: {10... ,1100... ,11110000... ,...}

... means that each 0 1 starting repeats on itself forever.

the array you wrote out - clearly it satisfies every row is eventually 1 continually (ie every entry in row r is 1 after point reading right to left - the point changing as r changes) therefore it corresponds to sets whose complement is finite. The cofinite sets again. now what about them.
 
  • #250
I don't understand it. I've proved one diagram corresponds only to the finite subsets, another corresponds only to the cofinite subsets, their union is not the power set, that organic doesn't know the meaning of the terms he uses, as proven by the fact that he thinks it's ok for a bijection not to be injective. what more do i need to do?
 
  • #251
Matt's talking about the rows, not the columns. I think we all agree there is a bijection between the set of columns and N.
 
  • #252
Originally posted by Organic
Matt,

What is finite in {10... ,1100... ,11110000... ,...} set?
I'm not saying anything there is a finite set. it's the same proof as before that you don't understand.

take the row at position r. let us examine what set it corresponds to in the power set.

now the c'th column starts with 2^c 1s doesn't it? that is the pattern of the columns.the c'th entry in row r is the r'th entry in column c. Now, 2^c>c and if c>r we see the r'th entry in column c is a 1.

therefore all entries after the r'th in row r are 1.look at the finite portion of the diagram - notice how everything above the diagonal is a 1? that's just what we've proved above.

and what that tells us is that the element in the power set correspoding to that row r contains every element in N greater than r. thus it's complement only contains some subset of the numbers 1,2,..r.

Sets like this are called cofinite.

This is the same method of proof that shows the other list only contained elements in ther power set that had a finite number of elements in them because there the any row eventually becomes zero by the same argument. thus you've only enumerated the finite and cofinite sets and none of the (uncountable) remaining sets.The cut off point is different in each row but that doesn't matter, which is what i think you thought i meant earlier - that there was a vertical line you could draw in the diagram and all to the left of the vertical line is 0 (or 1) I am not saying that and i don't need to say that.

read the above proof carefully, and try and understand we're just formally stating that everythin above the diagonal is a 1 (in this case and 0 in the other diagram)
 
  • #253
also note i am not saying a row is finite, but that a row corresponds to a cofinite (or finite in the old case) element in the power set of N
 
  • #254
Matt and Hurkyl,

What is finite in {10... ,1100... ,11110000... ,...} set?

This set is bijective to N.

Now, let us go back to look at this set like this:
Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
[b]{[/b]...,1,1,1,1[b]}[/b] 
 ...,1,1,1,0  
 ...,1,1,0,1  
 ...,1,1,0,0  
 ...,1,0,1,1  
 ...,1,0,1,0  
 ...,1,0,0,1  
 ...,1,0,0,0  
 ...,0,1,1,1  
 ...,0,1,1,0  
 ...,0,1,0,1  
 ...,0,1,0,0  
 ...,0,0,1,1  
 ...,0,0,1,0  
 ...,0,0,0,1  
 ...,0,0,0,0  
 ...
By taking the n-th notation from each member we can build a list of unique sequences which its magnitude=2^aleph0.
 
  • #255
n'th notation from what?

did you even bother to try to understand that argument? No i didn't think so.

we aren't saying the set of columns is finite. why would we? have you even read the proof i just offered? attempted to understand what it said? or did you just presume to know it was wrong? It isn't.
 
  • #256
Matt, if you write this: "n'th notation from what?" it is simply shows us that you did not read carefully what I write to you and to Hurkyl, so here it is again.



{10... ,1100... ,11110000... ,...} set is bijective to N.

By taking the n-th notation from each member we can build a list of unique sequences which its magnitude=2^aleph0:

Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
[b]{[/b]...,1,1,1,1[b]}[/b] 
 ...,1,1,1,0  
 ...,1,1,0,1  
 ...,1,1,0,0  
 ...,1,0,1,1  
 ...,1,0,1,0  
 ...,1,0,0,1  
 ...,1,0,0,0  
 ...,0,1,1,1  
 ...,0,1,1,0  
 ...,0,1,0,1  
 ...,0,1,0,0  
 ...,0,0,1,1  
 ...,0,0,1,0  
 ...,0,0,0,1  
 ...,0,0,0,0  
 ...
 
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  • #257
i've read and reread that post and you don't explain what the n'th notation is.

the indvidual words make sense but not when put together like that

what is a notation, what is the nth one? you didn't state what they are.

which members are you taking these notations from? members of rows, columns, power sets, N?

so illuminate it for the stupid round herenow have you actually read my proof that any row in the diagram corresponds to a confinite element of the power set?

we;ve got this diagram enumerating the cofinite sets, what's the point you're trying to make
 
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  • #258
Matt,

First, thank you for reading an rereading.


{10... ,1100... ,11110000... ,...} set is bijective to N.

The n-th notation of each member is:

Code:
n-th 1 2 3 . .  1 2 3 . . . .  1 2 3 . . . . . . . .  1 2 3
    {1 0 . . . ,1 1 0 0 . . . ,1 1 1 1 0 0 0 0 . . . ,. . .}

By taking the n-th notation from each member we can build a list of unique sequences which its magnitude=2^aleph0:

Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
[b]{[/b]...,1,1,1,1[b]}[/b]<--> n-th 1
 ...,1,1,1,0 <--> n-th 2
 ...,1,1,0,1 <--> n-th 3 
 ...,1,1,0,0 <--> n-th 4 
 ...,1,0,1,1 <--> n-th 5 
 ...,1,0,1,0 <--> n-th 6 
 ...,1,0,0,1 <--> n-th 7 
 ...,1,0,0,0 <--> n-th 8 
 ...,0,1,1,1 <--> n-th 9 
 ...,0,1,1,0 <--> n-th 10
 ...,0,1,0,1 <--> n-th 11
 ...,0,1,0,0 <--> n-th 12
 ...,0,0,1,1 <--> n-th 13
 ...,0,0,1,0 <--> n-th 14
 ...,0,0,0,1 <--> n-th 15
 ...,0,0,0,0 <--> n-th 16
 ...
 
  • #259
ok got it. you take the n'th element in each column as the elements in the nth row.

That does not give you "2^aleph-0" possibilities, there are exactly as many rows as there are natural numbers. How can you claim that there are 2^aleph-0 rows. Why? What set of cardinality 2^aleph-0 is it in bijection with and how?
 
  • #260
Matt,

A Binary Tree with infinitely many nodes has a width of magnitude aleph0 and a length of 2^aleph0.

Simple as that.
 
  • #261
That would depend on how you defined binary tree - the rooted binary tree with countably infinite branch set has only a countable number of nodes - it is the countable union of finite sets.

Besides that has nothing to do with this issue.

Of course you don't think that binary tree means what it really means.

So what is your binary tree? You seem to think it is a Cantor set. There fore you seem to think that the rows of your matrix are in bijection with a cantor set. How? Please demonstrate? As I can prove that a cantor set is not in bijection with N, that the rows are in bijection with N, don't you think that that is a little problematic. So please exhibit this notional bijection with the Cantor set. Or explicitly state what your binary tree is. This will all involve taking (inverse/direct) limits in the correct sense, but of course you know all about thatedit: and seeing as you don't think there are an uncountable number of points in the real line, don't you think taking an uncountable subset is wrong? It is conceptually impossible in your world, and if you're in mine you need to prove all your assertions.
 
  • #262
Fun fact.

A (balanced) binary tree with infinitely many nodes has zero leaves.
 
  • #263
Matt and Hurkyl,
Besides that has nothing to do with this issue (the Binary Tree).

Let us take again our set:
Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
[b]{[/b]...,1,1,1,1[b]}[/b]<--> n-th 1
 ...,1,1,1,0 <--> n-th 2
 ...,1,1,0,1 <--> n-th 3 
 ...,1,1,0,0 <--> n-th 4 
 ...,1,0,1,1 <--> n-th 5 
 ...,1,0,1,0 <--> n-th 6 
 ...,1,0,0,1 <--> n-th 7 
 ...,1,0,0,0 <--> n-th 8 
 ...,0,1,1,1 <--> n-th 9 
 ...,0,1,1,0 <--> n-th 10
 ...,0,1,0,1 <--> n-th 11
 ...,0,1,0,0 <--> n-th 12
 ...,0,0,1,1 <--> n-th 13
 ...,0,0,1,0 <--> n-th 14
 ...,0,0,0,1 <--> n-th 15
 ...,0,0,0,0 <--> n-th 16
 ...
Now let us make a little redundancy diet
Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
...  1-1-1-1 <--> n-th 1
     \  \ \0 <--> n-th 2
      \  0-1 <--> n-th 3 
       \  \0 <--> n-th 4 
       0-1-1 <--> n-th 5 
        \ \0 <--> n-th 6 
         0-1 <--> n-th 7 
          \0 <--> n-th 8 
 ... 0-1-1-1 <--> n-th 9 
     \  \ \0 <--> n-th 10
      \  0-1 <--> n-th 11
       \  \0 <--> n-th 12
       0-1-1 <--> n-th 13
        \ \0 <--> n-th 14
         0-1 <--> n-th 15
          \0 <--> n-th 16
 ...
and we got
Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
          /1 <--> n-th 1
         1 
        / \0 <--> n-th 2
       1   
       /\ /1 <--> n-th 3 
      /  0
     /    \0 <--> n-th 4 
 ... 1    
     \    /1 <--> n-th 5 
      \  1 
       \/ \0 <--> n-th 6
       0  
        \ /1 <--> n-th 7
         0
          \0 <--> n-th 8
          
          /1 <--> n-th 9 
         1
        / \0 <--> n-th 10
       1  
       /\ /1 <--> n-th 11
      /  0 
     /    \0 <--> n-th 12
 ... 0    
     \    /1 <--> n-th 13
      \  1
       \/ \0 <--> n-th 14
       0  
        \ /1 <--> n-th 15
         0
          \0 <--> n-th 16
 ...
 
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  • #264
Full credit to him, it takes some doing to talk about binary trees (uniquely path connected), even drawing them so they appear to be what you I might think, and then after much pressing claim it is actually a Cantor Set (totally disconnected), and further that as this is TD he can do whatever he damn well pleases. (Despite the fact it was your decision to move it here, Hurkyl, and that he wanted to post it in the maths forum.) That's some cheek
 
  • #265
And is that supposed to demonstrate a bijection with the Cantor set? How?

If it helps, a Cantor set is in bijection with the set of base 3 expansions of all reals between 0 and 1 with no 2 in their expansions, with the obivious dyadic representations identified.
 
  • #266
Matt and Hurkyl,
Code:
      3 2 1 0
     2 2 2 2
     ^ ^ ^ ^
     | | | |
     v v v v
          /1 <--> n-th 1
         1 
        / \0 <--> n-th 2
       1   
       /\ /1 <--> n-th 3 
      /  0
     /    \0 <--> n-th 4 
 ... 1    
     \    /1 <--> n-th 5 
      \  1 
       \/ \0 <--> n-th 6
       0  
        \ /1 <--> n-th 7
         0
          \0 <--> n-th 8
          
          /1 <--> n-th 9 
         1
        / \0 <--> n-th 10
       1  
       /\ /1 <--> n-th 11
      /  0 
     /    \0 <--> n-th 12
 ... 0    
     \    /1 <--> n-th 13
      \  1
       \/ \0 <--> n-th 14
       0  
        \ /1 <--> n-th 15
         0
          \0 <--> n-th 16
 ...
 
  • #267
Matt,

Please look at http://www.mathacademy.com/pr/prime/articles/cantset/

Cantor set is a hybrid of base 2 and base 3 ratios.

Therefore it is easy to show that 2^aleph0 is Cantor set where Cantor set is a Binary Tree:
Code:
                ?
__________________________________

      1                    0
_____________        _____________

  1       0            1       0
_____   _____        _____   _____

1  0    1  0         1  0    1  0  
__ __   __ __        __ __   __ __
 
Last edited:
  • #268
And? That is not a bijection from the (countable) set of rows corresponding to cofinite elements the power set of N to the Cantor Set, or any thing that has cardinality 2^aleph-0It tells you how to superimpose a binary tree onto another picture. that does not define a bijection. Nor does it imply that the binary tree is 'uncountable' (what aspect of it is uncountable in your opinion)
 
  • #269
Organic, I know what a Cantor set is.
You claimied the binary tree was a Cantor set in this thread earlier. It isn't. One wonders what you think a Cantor set is, or a binary tree.

Or why that defines a bijection.
 
  • #270
Matt,

You forget my proof |R|>|N| but both N and R are countable.
 

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