Cardinality of the set of binary-expressed real numbers

In summary: This simple argument should make it clear that Cantor's diagonal argument is not about the cardinality of the natural numbers, but about the cardinality of the real numbers. It's a completely different argument, with different assumptions and a different conclusion. I hope this helps!In summary, the conversation discussed the cardinality of the set of binary-expressed real numbers and its implications. It also delved into Cantor's diagonal argument and the continuum hypothesis. However, the article mentioned in the conversation contained several incorrect reasoning and errors, and it was suggested to refer to a reliable source for a better understanding of set theory. The conversation also clarified that the Grand Hotel analogy has nothing to do with Cantor's diagonal argument and that the latter
  • #1
PengKuan
10
0
Cardinality of the set of binary-expressed real numbers
This article gives the cardinal number of the set of all binary numbers by counting its elements, analyses the consequences of the found value and discusses Cantor's diagonal argument, power set and the continuum hypothesis.
1. Counting the fractional binary numbers
2. Fractional binary numbers on the real line
3. Countability of BF
4. Set of all binary numbers, B
5. On Cantor's diagonal argument
6. On Cantor's theorem
7. On infinite digital expansion of irrational number
8. On the continuum hypothesis

Please read the article at
Cardinality of the set of binary-expressed real numbers
http://pengkuanonmaths.blogspot.com/2015/12/cardinality-of-set-of-binary-expressed.html
or
https://www.academia.edu/19403597/Cardinality_of_the_set_of_binary-expressed_real_numbers
 
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  • #2
Sorry, it's wrong. You say there are ##2^n## "fractional numbers" with ##n## decimals. Correct so far. But then you say "let ##n## go to infinity and you obtain ##2^{\aleph_0}##". This is an incorrect reasoning. Cardinalities do not work like this.

There are other very obvious errors in your paper. I suggest to pick up the excellent book "Introduction to set theory" by Hrbacek and Jech and work through it carefully.

Also, if you claim to have found an error in Cantor's diagonal argument, then it is not ok to make some kind of analogy with the Hilbert grand Hotel. Instead, you need to specify where exactly the error is. In particular, here is the complete rigorous proof of "the reals are uncountable" http://us.metamath.org/mpegif/ruc.html Every single logical step is detailed from the axioms. You need to say exactly which step is not allowed and why. Otherwise, nobody will take you seriously.
 
  • #3
micromass said:
Sorry, it's wrong. You say there are ##2^n## "fractional numbers" with ##n## decimals. Correct so far. But then you say "let ##n## go to infinity and you obtain ##2^{\aleph_0}##". This is an incorrect reasoning. Cardinalities do not work like this.

There are other very obvious errors in your paper. I suggest to pick up the excellent book "Introduction to set theory" by Hrbacek and Jech and work through it carefully.

Also, if you claim to have found an error in Cantor's diagonal argument, then it is not ok to make some kind of analogy with the Hilbert grand Hotel. Instead, you need to specify where exactly the error is. In particular, here is the complete rigorous proof of "the reals are uncountable" http://us.metamath.org/mpegif/ruc.html Every single logical step is detailed from the axioms. You need to say exactly which step is not allowed and why. Otherwise, nobody will take you seriously.
Thank for replying so fast.

I have given detailed my reasoning about diagonal argument after the Grand hotel. I will read your link.
 
  • #4
PengKuan said:
Thank for replying so fast.

I have given detailed my reasoning about diagonal argument after the Grand hotel. I will read your link.

Well, your reasoning is wrong in any case and shows you do not really grasp set theory well. In particular, the proof by contradiction.
 
  • #5
PengKuan said:
Thank for replying so fast.

I have given detailed my reasoning about diagonal argument after the Grand hotel. I will read your link.
I might be restating what micromass already said, but in your example of the Grand Hotel, to find a room for one more guest, all that needs to happen is that each current guest gets moved from room N to room N + 1 (where ##N \ge 1##), thereby freeing up room 1. The new guest can be assigned that room (room 1). The argument is a lot simpler than what you have described, and has nothing to do with Cantor's diagonal argument.

A similar argument can be used to accommodate any finite number of guests, simply by shifting each current occupant from room N to room N + k, where k is the number of new arrivals. The hotel can also accommodate a (countably) infinite number of new guests, by shifting each current occupant from room N to room 2N, thereby freeing up rooms 1, 3, 5, ..., 2N + 1, ... for the new arrivals.
 

What is the definition of the cardinality of the set of binary-expressed real numbers?

The cardinality of a set is the number of elements in that set. In the case of binary-expressed real numbers, it refers to the number of unique real numbers that can be expressed using only the digits 0 and 1 in binary form.

Is the cardinality of the set of binary-expressed real numbers countable or uncountable?

The cardinality of the set of binary-expressed real numbers is uncountable. This means that there is no way to list all the elements of the set in a sequential manner.

How does the cardinality of the set of binary-expressed real numbers compare to the cardinality of the set of all real numbers?

The cardinality of the set of binary-expressed real numbers is equal to the cardinality of the set of all real numbers, as every real number can be expressed in binary form using only the digits 0 and 1.

Can the cardinality of the set of binary-expressed real numbers be proven mathematically?

Yes, the cardinality of the set of binary-expressed real numbers can be proven using Cantor's diagonalization argument, which shows that the set is uncountable.

What implications does the uncountability of the set of binary-expressed real numbers have in mathematics and computer science?

The uncountability of the set of binary-expressed real numbers has important implications in fields such as measure theory, probability theory, and computer science. It also has practical applications in areas such as data compression and encryption.

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