I Maybe all reals can be listed?

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The discussion centers on the concept of listing real numbers and the implications of Cantor's diagonal argument. Participants explore the idea that while diagonalization shows that not all reals can be listed, it does not conclusively prove that all reals cannot be counted. Various methods, including binary trees and mirroring techniques, are proposed to challenge the notion that a complete list of reals is possible. The argument emphasizes that any proposed list will always miss at least one real number, reinforcing the idea that the reals cannot be fully enumerated. Ultimately, the conversation highlights the complexity of proving the uncountability of real numbers and the limitations of existing arguments.
  • #31
There is no mathematical term "closed list".
There are sets closed in some topology, but that is unrelated to the topic here.
 
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  • #32
??

There are an infinite number of diagonals in a list. For every coordinate, the are 4 diagonals, in an infinite list, there are an infinite number of coordinates.

Ok, name it what you want then *shrug* It's obviously pertinent that there are "closed lists" in real number list representation, particularly when the topic talks about diagonalization, which is what we're discussing. You blankly stated that Cantor proved once and for all, that diagonalization proved uncountability. That's not true, there are "closed lists". I just proved one right in front of you, why do I need a source for it to be proven to you?

Additionally, "closed lists" have been found for lists of irrationals, though the lists were shown to not be complete.

The open question is whether the incompleteness is inherent or whether it's a sequence problem?

Like I explained before, if you list all the counting numbers first, you can't list all the rationals "next", because the counting numbers go forever. BUT! You can interpolate them (called scattering) and if you scatter them, you can make a whole list of the rationals… to do this, the sequence has to be very precise. When adding irrationals, obviously, the only way to include them is to interpolate them with the rationals, because, again, the new list of all rationals goes on forever, and you can't tack the irrationals at "the end".

Cantor could have just run into a sequencing problem, and considered it a proof. We already know lists can be constructed that contain their diagonals - so the question isn't in my mind, resolved. You can argue dimensional flooding, and I can come back and say you have a sequencing problem… but to do this, I have to solve, not just state, the scattering sequence that proves the dimensional flooding can be listed - at least in order to prove you wrong.

In saying this, it is extremely easy to see dimensional flooding from a sequencing error, and assume it can't be done, when all it really is, is a sequencing error.
 
  • #33
You keep using words in ways different from their usual meaning, together with expressions apparently invented by you, and when asked what you mean you don't explain it. A discussion cannot work that way. I closed the thread.
 

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